Stable percarboxylic acid compositions and uses thereof

ABSTRACT

The present invention relates generally to stable percarboxylic acid compositions comprising, inter alia, at least two stabilizing agents, and various uses for water treatments, including water treatments in connection with oil- and gas-field operations. The present invention also relates to slick water compositions and gel based compositions that comprise stable percarboxylic acid compositions and the use thereof in oil- and gas-field operations.

CROSS REFERENCES TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No.15/076,516, filed Mar. 21, 2016, entitled “STABLE PERCARBOXYLIC ACIDCOMPOSITIONS AND USES THEREOF,” now allowed, which is a continuation ofU.S. application Ser. No. 13/844,515, filed Mar. 15, 2013, and entitled“Stable Peroxycarboxylic Acid Compositions and Uses Thereof,” now U.S.Pat. No. 9,321,664 B2, which claims benefit of priority of U.S.provisional application Ser. No. 61/710,631, filed Oct. 5, 2012, andentitled “Stable Peroxycarboxylic Acid Compositions and Uses Thereof,”and U.S. provisional application Ser. No. 61/762,777, filed Feb. 8,2013, and entitled “Stable Peroxycarboxylic Acid Compositions and UsesThereof.” The present application also relates to U.S. provisionalapplication Ser. No. 61/617,814, filed Mar. 31, 2012, and entitled “Useof Peracetic Acid/Hydrogen Peroxide and Catalase for Treatment ofDrilling Fluids, FRAC Fluids, Flowback Water and Disposal Water”; U.S.application Ser. No. 13/331,104, filed Dec. 20, 2011, and entitled“Generation of Peroxycarboxylic Acids at Alkaline pH, and Their Use asTextile Bleaching and Antimicrobial Agents”; U.S. application Ser. No.13/331,304, filed Dec. 20, 2011, and entitled “In Situ Generation ofPeroxycarboxylic Acids at Alkaline pH, and Methods of Use Thereof”; andU.S. application Ser. No. 13/331,486, filed Dec. 20, 2011, and entitled“In Situ Generation of Peroxycarboxylic Acids at Alkaline pH, andMethods of Use Thereof.” The contents of the above-referencedapplications are incorporated by reference in their entireties for allpurposes.

TECHNICAL FIELD

The present invention relates generally to stable percarboxylic acidcompositions comprising, inter alia, at least two stabilizing agents,and various uses for water treatments, including water treatments inconnection with oil- and gas-field operations. The present inventionalso relates to slick water compositions and gel based compositions thatcomprise stable percarboxylic acid compositions and the use thereof inoil- and gas-field operations.

BACKGROUND OF THE INVENTION

Peroxycarboxylic acids are increasingly used as biocides in variousfields owing to their broad biocidal efficacy and excellentenvironmental profiles. The most commonly used peroxycarboxylic acid isperacetic acid. Peracetic acid is a colorless, freely water solubleliquid which has great biocidal efficacy toward various microorganisms,such as bacteria, virus, yeast, fungi and spores. When decomposed,peracetic acid results in acetic acid (vinegar), water and oxygen. Pureperoxycarboxylic acids, such as peracetic acid, however, are unstableand explosive, and thus commercially available peroxycarboxylic acidsare usually sold in an equilibrium solution. In addition to theperoxycarboxylic acid, an equilibrium solution also contains thecorresponding carboxylic acid, hydrogen peroxide and water. Compared tothe peroxycarboxylic acid, hydrogen peroxide only has negligiblebiocidal efficacy, but may pose environmental issues in someapplications if it exceeds the specific release limitation. Furthermore,it has been disclosed that the presence of hydrogen peroxide hasnegative impacts on the efficacy of peroxycarboxylic acid toward somemicroorganisms.

In applications such as water treatment for use in fracturing drillingof oil and gas wells, the hydrogen peroxide that is in theperoxycarboxylic acid compositions may interact with other componentsused in the applications, such as gelling agents, friction reducers,corrosion inhibitors and scale inhibitors, etc. The presence of hydrogenperoxide in these solutions may cause the performance failure. Thus,there is a need to develop a peroxycarboxylic acid composition which hasas high as possible peroxycarboxylic acid to hydrogen peroxide ratio forapplications as a biocide in general, and in particular for watertreatment in oil and gas drilling.

Commercially available peroxycarboxylic acid compositions generally havesignificantly less, or roughly equal, weight amounts of peroxycarboxylicacid than hydrogen peroxide. It is known that among other factors, theratio of hydrogen peroxide to peroxycarboxylic acid plays a significantrole in the stability of the peroxycarboxylic acid compositions. Thehigher the ratio of hydrogen peroxide to peroxycarboxylic acid, the morestable of the composition.

Some commonly available peroxycarboxylic acid compositions have a ratioof about 1.5 to 1 hydrogen peroxide to peroxycarboxylic acid. Whilecompositions with higher ratio of peroxycarboxylic acid to hydrogenperoxide are commercially available, these compositions are in smallpackaging sizes limited by self accelerating decomposition temperature(SADT) transportation limitations and require controlled temperaturestorage due to the limited stability of the compositions.

Various stabilizers are used in peroxycarboxylic acid compositions tostabilize the compositions. For example, pyridine carboxylic acid basedstabilizers, such as picolinic acid and salts, pyridine-2,6-dicarboxylicacid and salts, and phosphonate based stabilizers, such as phosphoricacid and salts, pyrophosphoric acid and salts and most commonly1-hydroxyethylidene-1,1-diphosphonic acid (HEDP) and salts, are used.When used individually at the right level, these stabilizers cansignificantly improve the stability of the peroxycarboxylic acidcompositions, and for the conventional peroxycarboxylic acidcompositions, the stability profile achieved with these stabilizersallows for the commercial use of these compositions. Forperoxycarboxylic acid compositions with high ratios of peroxycarboxylicacid to hydrogen peroxide, the extra stability challenge cannot be metby these stabilizers used in the traditional matter.

BRIEF SUMMARY OF THE INVENTION

The present invention relates to stable percarboxylic acid compositionsand uses thereof. In some embodiments, the present invention relates toa stable peracid composition with high ratio of peracid to hydrogenperoxide. Optionally, the level of hydrogen peroxide is further reducedby adding a catalase or peroxidase either in use solution, or in thediluted concentrate prior to use. The compositions disclosed areparticularly useful in treating the water for use in fracturing drillingof oil and gas well.

In one aspect, the present invention is directed to a composition, whichcomposition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;        -   or a salt thereof;        -   or a compound having the following Formula (IB):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;    -   5) a second stabilizing agent, which is a compound having the        following Formula (IIA):

-   -   wherein    -   R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and    -   R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;    -   or a salt thereof;    -   or a compound having the following Formula (IIB):

-   -   wherein    -   R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   or a salt thereof; and    -   wherein said hydrogen peroxide has a concentration of at least        about 0.1 wt-%, the C₁-C₂₂ percarboxylic acid has a        concentration of at least about 2 times of the concentration of        said hydrogen peroxide, and said composition has a pH at about 4        or less.

In another aspect, the present invention is directed to a method forstoring a percarboxylic acid containing composition, which methodcomprises storing the above composition, wherein said compositionretains at least about 80% of the C₁-C₂₂ percarboxylic acid activityafter storage of about 30 days at about 50° C.

In still another aspect, the present invention is directed to a methodfor transporting a percarboxylic acid containing composition, whichmethod comprises transporting the above composition, preferably in bulk,wherein the SADT of said composition is elevated to at least 45° C.during transportation.

In yet another aspect, the present invention is directed to a method fortreating water, which method comprises providing the above compositionto a water source in need of treatment to form a treated water source,wherein said treated water source comprises from about 1 ppm to about1,000 ppm of said C₁-C₂₂ percarboxylic acid.

In yet another aspect, the present invention is directed to a method fortreating a target, which method comprises a step of contacting a targetwith the above composition in a diluted level to form a treated targetcomposition, wherein said treated target composition comprises fromabout 1 ppm to about 10,000 ppm of said C₁-C₂₂ percarboxylic acid, andsaid contacting step lasts for sufficient time to stabilize or reducemicrobial population in and/or on said target or said treated targetcomposition.

In yet another aspect, the present invention is directed to a method forreducing the level of hydrogen sulfide (H₂S), hydrosulfuric acid or asalt thereof in a water source, which method comprises a step ofcontacting a water source with the above composition in a diluted levelto form a treated water source, wherein said treated water sourcecomprises from about 1 ppm to about 10,000 ppm of said C₁-C₂₂percarboxylic acid, and said contacting step lasts for sufficient timeto stabilize or reduce the level of H₂S, hydrosulfuric acid or a saltthereof in said treated water source.

The present invention also relates to slick water compositions useful inoil and/or gas drilling that comprise stable percarboxylic acidcompositions and uses thereof. In one aspect, the present invention isdirected to a composition, which composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;        -   or a salt thereof;        -   or a compound having the following Formula (TB):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;        -   5) a second stabilizing agent, which is a compound having            the following Formula (IIA):

-   -   wherein    -   R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and    -   R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;    -   or a salt thereof;    -   or a compound having the following Formula (IIB):

-   -   wherein    -   R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   or a salt thereof;        -   6) a friction reducer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 20 ppm, and the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

In another aspect, the present invention is directed to a method forslick water fracturing, which method comprises directing the abovecomposition into a subterranean environment.

The present invention further relates to gel based compositions usefulin oil and/or gas drilling that comprise stable percarboxylic acidcompositions and uses thereof. In one aspect, the present invention isdirected to a composition, which composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;    -   or a compound having the following Formula (TB):

-   -   wherein    -   R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —R^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;        -   a second stabilizing agent, which is a compound having the            following Formula (IIA):

-   -   wherein    -   R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and    -   R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;    -   or a salt thereof;    -   or a compound having the following Formula (IIB):

wherein

-   -   R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl,        (C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;    -   or a salt thereof;        -   5) a viscosity enhancer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 15 ppm, and said C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

In another aspect, the present invention is directed to a method forhigh-viscosity fracturing, which method comprises directing the abovecomposition into a subterranean environment.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates stability of peracetic acid compositions with variousstabilizers.

FIG. 2 illustrates synergistic stabilizing performance of HEDP and DPA.

FIG. 3 illustrates SADT test of peracetic acid compositions with variousstabilizers.

FIG. 4 illustrates kinetic viscosity profile of POAA with various levelsof H₂O₂ in a gel fluid.

FIGS. 5A and 5B illustrate an example of H₂S reduction using variouslevels of formulations 13523-37-1 and 13523-37-2.

FIGS. 6A and 6B illustrate another example of H₂S reduction usingvarious levels of formulations 13523-37-1 and 13523-37-2.

DETAILED DESCRIPTION OF THE INVENTION

For clarity of disclosure, and not by way of limitation, the detaileddescription of the invention is divided into the subsections thatfollow.

A. DEFINITIONS

Unless defined otherwise, all technical and scientific terms used hereinhave the same meaning as is commonly understood by one of ordinary skillin the art to which this invention belongs. All patents, applications,published applications and other publications referred to herein areincorporated by reference in their entireties. If a definition set forthin this section is contrary to or otherwise inconsistent with adefinition set forth in the patents, applications, publishedapplications and other publications that are herein incorporated byreference, the definition set forth in this section prevails over thedefinition that is incorporated herein by reference.

The embodiments of this invention are not limited to particularperoxycarboxylic acid compositions and methods for using the same, whichcan vary and are understood by skilled artisans. It is further to beunderstood that all terminology used herein is for the purpose ofdescribing particular embodiments only, and is not intended to belimiting in any manner or scope. For example, all units, prefixes, andsymbols may be denoted in its SI accepted form. Numeric ranges recitedwithin the specification are inclusive of the numbers defining the rangeand include each integer within the defined range.

It should be noted that, as used in this specification and the appendedclaims, the singular forms “a,” “an,” and “the” include plural referentsunless the content clearly dictates otherwise. Thus, for example,reference to a composition containing “a compound” includes acomposition having two or more compounds. It should also be noted thatthe term “or” is generally employed in its sense including “and/or”unless the content clearly dictates otherwise.

So that the present invention may be more readily understood, certainterms are first defined. Unless defined otherwise, all technical andscientific terms used herein have the same meaning as commonlyunderstood by one of ordinary skill in the art to which embodiments ofthe invention pertain. Many methods and materials similar, modified, orequivalent to those described herein can be used in the practice of theembodiments of the present invention without undue experimentation, thepreferred materials and methods are described herein. In describing andclaiming the embodiments of the present invention, the followingterminology will be used in accordance with the definitions set outbelow.

As used herein, the term “about” refers to variation in the numericalquantity that can occur, for example, through typical measuring andliquid handling procedures used for making concentrates or use solutionsin the real world; through inadvertent error in these procedures;through differences in the manufacture, source, or purity of theingredients used to make the compositions or carry out the methods; andthe like. The term “about” also encompasses amounts that differ due todifferent equilibrium conditions for a composition resulting from aparticular initial mixture. Whether or not modified by the term “about”,the claims include equivalents to the quantities.

The term “cleaning,” as used herein, means to perform or aid in soilremoval, bleaching, microbial population reduction, or combinationthereof. For the purpose of this patent application, successfulmicrobial reduction is achieved when the microbial populations arereduced by at least about 50%, or by significantly more than is achievedby a wash with water. Larger reductions in microbial population providegreater levels of protection.

As used herein, “consisting essentially of” means that the methods andcompositions may include additional steps, components, ingredients orthe like, but only if the additional steps, components and/oringredients do not materially alter the basic and novel characteristicsof the claimed methods and compositions.

As used herein, the term “disinfectant” refers to an agent that killsall vegetative cells including most recognized pathogenicmicroorganisms, using the procedure described in A.O.A.C. Use DilutionMethods, Official Methods of Analysis of the Association of OfficialAnalytical Chemists, paragraph 955.14 and applicable sections, 15thEdition, 1990 (EPA Guideline 91-2). As used herein, the term “high leveldisinfection” or “high level disinfectant” refers to a compound orcomposition that kills substantially all organisms, except high levelsof bacterial spores, and is effected with a chemical germicide clearedfor marketing as a sterilant by the Food and Drug Administration. Asused herein, the term “intermediate-level disinfection” or “intermediatelevel disinfectant” refers to a compound or composition that killsmycobacteria, most viruses, and bacteria with a chemical germicideregistered as a tuberculocide by the Environmental Protection Agency(EPA). As used herein, the term “low-level disinfection” or “low leveldisinfectant” refers to a compound or composition that kills someviruses and bacteria with a chemical germicide registered as a hospitaldisinfectant by the EPA.

As used herein, the term “free,” “no,” “substantially no” or“substantially free” refers to a composition, mixture, or ingredientthat does not contain a particular compound or to which a particularcompound or a particular compound-containing compound has not beenadded. In some embodiments, the reduction and/or elimination of hydrogenperoxide according to embodiments provide hydrogen peroxide-free orsubstantially-free compositions. Should the particular compound bepresent through contamination and/or use in a minimal amount of acomposition, mixture, or ingredients, the amount of the compound shallbe less than about 3 wt-%. More preferably, the amount of the compoundis less than 2 wt-%, less than 1 wt-%, and most preferably the amount ofthe compound is less than 0.5 wt-%.

As used herein, the term “microorganism” refers to any noncellular orunicellular (including colonial) organism. Microorganisms include allprokaryotes. Microorganisms include bacteria (including cyanobacteria),spores, lichens, fungi, protozoa, virinos, viroids, viruses, phages, andsome algae. As used herein, the term “microbe” is synonymous withmicroorganism.

As used herein, the terms “mixed” or “mixture” when used relating to“percarboxylic acid composition,” “percarboxylic acids,”“peroxycarboxylic acid composition” or “peroxycarboxylic acids” refer toa composition or mixture including more than one percarboxylic acid orperoxycarboxylic acid.

As used herein, the term “sanitizer” refers to an agent that reduces thenumber of bacterial contaminants to safe levels as judged by publichealth requirements. In an embodiment, sanitizers for use in thisinvention will provide at least a 99.999% reduction (5-log orderreduction). These reductions can be evaluated using a procedure set outin Germicidal and Detergent Sanitizing Action of Disinfectants, OfficialMethods of Analysis of the Association of Official Analytical Chemists,paragraph 960.09 and applicable sections, 15th Edition, 1990 (EPAGuideline 91-2). According to this reference a sanitizer should providea 99.999% reduction (5-log order reduction) within 30 seconds at roomtemperature, 25±2° C., against several test organisms.

Differentiation of antimicrobial “-cidal” or “-static” activity, thedefinitions which describe the degree of efficacy, and the officiallaboratory protocols for measuring this efficacy are considerations forunderstanding the relevance of antimicrobial agents and compositions.Antimicrobial compositions can affect two kinds of microbial celldamage. The first is a lethal, irreversible action resulting in completemicrobial cell destruction or incapacitation. The second type of celldamage is reversible, such that if the organism is rendered free of theagent, it can again multiply. The former is termed microbiocidal and thelater, microbistatic. A sanitizer and a disinfectant are, by definition,agents which provide antimicrobial or microbiocidal activity. Incontrast, a preservative is generally described as an inhibitor ormicrobistatic composition.

As used herein, the term “water” for treatment according to theinvention includes a variety of sources, such as freshwater, pond water,sea water, salt water or brine source, brackish water, recycled water,or the like. Waters are also understood to optionally include both freshand recycled water sources (e.g. “produced waters”), as well as anycombination of waters for treatment according to the invention. In someembodiments, produced water (or reuse water) refers to a mixture ofwater that comprises both water recycled from previous or concurrentoil- and gas-field operations, e.g., fracking, and water that has notbeen used in oil- and gas-field operations, e.g., fresh water, pondwater, sea water, etc.

As used herein, “weight percent,” “wt-%,” “percent by weight,” “% byweight,” and variations thereof refer to the concentration of asubstance as the weight of that substance divided by the total weight ofthe composition and multiplied by 100. It is understood that, as usedhere, “percent,” “%,” and the like are intended to be synonymous with“weight percent,” “wt-%,” etc.

It is understood that aspects and embodiments of the invention describedherein include “consisting” and/or “consisting essentially of” aspectsand embodiments.

Throughout this disclosure, various aspects of this invention arepresented in a range format. It should be understood that thedescription in range format is merely for convenience and brevity andshould not be construed as an inflexible limitation on the scope of theinvention. Accordingly, the description of a range should be consideredto have specifically disclosed all the possible sub-ranges as well asindividual numerical values within that range. For example, descriptionof a range such as from 1 to 6 should be considered to have specificallydisclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from2 to 4, from 2 to 6, from 3 to 6 etc., as well as individual numberswithin that range, for example, 1, 2, 3, 4, 5, and 6. This appliesregardless of the breadth of the range.

Other objects, advantages and features of the present invention willbecome apparent from the following specification taken in conjunctionwith the accompanying drawings.

B. STABLE PERCARBOXYLIC ACID COMPOSITIONS AND USES THEREOF

The present invention relates to stable percarboxylic acid compositionsand uses thereof. In one aspect, the present invention is directed to acomposition, which composition comprises:

-   -   a C₁-C₂₂ carboxylic acid;    -   a C₁-C₂₂ percarboxylic acid;    -   hydrogen peroxide;    -   a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

-   -   wherein    -   R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;        -   or a salt thereof;        -   or a compound having the following Formula (TB):

-   -   wherein    -   R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or wherein R^(2a) and R^(2b) are independently hydrogen        or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;        -   a second stabilizing agent, which is a compound having the            following Formula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof; and

wherein said hydrogen peroxide has a concentration of at least about 0.1wt-%, the C₁-C₂₂ percarboxylic acid has a concentration of at leastabout 2 times of the concentration of said hydrogen peroxide, and saidcomposition has a pH at about 4 or less.

In some embodiments, the present composition is an equilibratedcomposition that comprises peracid, hydrogen peroxide, carboxylic acidand a solvent, e.g., water. In some embodiments, the present compositiondoes not comprise a mineral acid, e.g., the mineral acids disclosed inWO 91/07375.

The C₁-C₂₂ percarboxylic acid can be used at any suitable concentrationrelative to the concentration of the hydrogen peroxide. In someembodiments, the C₁-C₂₂ percarboxylic acid has a concentration of atleast about 6 times of the concentration of the hydrogen peroxide. Inother embodiments, the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 10 times of the concentration of the hydrogen peroxide.In still other embodiments, the C₁-C₂₂ percarboxylic acid has aconcentration of at least about 6, 7, 8, 9 or 10 times of theconcentration of the hydrogen peroxide.

Carboxylic Acid

The present invention includes a carboxylic acid with the peracidcomposition and hydrogen peroxide. A carboxylic acid includes anycompound of the formula R—(COOH)_(n) in which R can be hydrogen, alkyl,alkenyl, alkyne, acylic, alicyclic group, aryl, heteroaryl, orheterocylic group, and n is 1, 2, or 3. Preferably R includes hydrogen,alkyl, or alkenyl. The terms “alkyl,” “alkenyl,” “alkyne,” “acylic,”“alicyclic group,” “aryl,” “heteroaryl,” and “heterocyclic group” are asdefined below with respect to peracids.

Examples of suitable carboxylic acids according to the equilibriumsystems of peracids according to the invention include a varietymonocarboxylic acids, dicarboxylic acids, and tricarboxylic acids.Monocarboxylic acids include, for example, formic acid, acetic acid,propanoic acid, butanoic acid, pentanoic acid, hexanoic acid, heptanoicacid, octanoic acid, nonanoic acid, decanoic acid, undecanoic acid,dodecanoic acid, glycolic acid, lactic acid, salicylic acid,acetylsalicylic acid, mandelic acid, etc. Dicarboxylic acids include,for example, adipic acid, fumaric acid, glutaric acid, maleic acid,succinic acid, malic acid, tartaric acid, etc. Tricarboxylic acidsinclude, for example, citric acid, trimellitic acid, isocitric acid,agaicic acid, etc.

In an aspect of the invention, a particularly well suited carboxylicacid is water soluble such as formic acid, acetic acid, propionic acid,butanoic acid, lactic acid, glycolic acid, citric acid, mandelic acid,glutaric acid, maleic acid, malic acid, adipic acid, succinic acid,tartaric acid, etc. Preferably a composition of the invention includesacetic acid, octanoic acid, or propionic acid, lactic acid, heptanoicacid, octanoic acid, or nonanoic acid.

Additional examples of suitable carboxylic acids are employed insulfoperoxycarboxylic acid or sulfonated peracid systems, which aredisclosed in U.S. Patent Publication Nos. 2010/0021557, 2010/0048730 and2012/0052134 herein incorporated by reference in their entireties.

Any suitable C₁-C₂₂ carboxylic acid can be used in the presentcompositions. In some embodiments, the C₁-C₂₂ carboxylic acid is aC₂-C₂₀ carboxylic acid. In other embodiments, the C₁-C₂₂ carboxylic acidis a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂, C₁₃, C₁₄, C₁₅,C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ carboxylic acid. In still otherembodiments, the C₁-C₂₂ carboxylic acid comprises acetic acid, octanoicacid and/or sulfonated oleic acid.

The C₁-C₂₂ carboxylic acid can be used at any suitable concentration. Insome embodiments, the C₁-C₂₂ carboxylic acid has a concentration fromabout 10 wt-% to about 90 wt-%. In other embodiments, the C₁-C₂₂carboxylic acid has a concentration from about 20 wt-% to about 80 wt-%.In still other embodiments, the C₁-C₂₂ carboxylic acid has aconcentration at about 10 wt-%, 20 wt-%, 30 wt-%, 40 wt-%, 50 wt-%, 60wt-%, 70 wt-%, 80 wt-%, or 90 wt-%.

Peracids

In some aspects, a peracid is included for antimicrobial efficacy in thecompositions. As used herein, the term “peracid” may also be referred toas a “percarboxylic acid” or “peroxyacid.” Sulfoperoxycarboxylic acids,sulfonated peracids and sulfonated peroxycarboxylic acids are alsoincluded within the term “peracid” as used herein. The terms“sulfoperoxycarboxylic acid,” “sulfonated peracid,” or “sulfonatedperoxycarboxylic acid” refers to the peroxycarboxylic acid form of asulfonated carboxylic acid as disclosed in U.S. Patent Publication Nos.2010/0021557, 2010/0048730 and 2012/0052134 which are incorporatedherein by reference in their entireties. A peracid refers to an acidhaving the hydrogen of the hydroxyl group in carboxylic acid replaced bya hydroxy group. Oxidizing peracids may also be referred to herein asperoxycarboxylic acids.

A peracid includes any compound of the formula R—(COOOH)_(n) in which Rcan be hydrogen, alkyl, alkenyl, alkyne, acylic, alicyclic group, aryl,heteroaryl, or heterocyclic group, and

-   -   n is 1, 2, or 3, and named by prefixing the parent acid with        peroxy. Preferably R includes hydrogen, alkyl, or alkenyl. The        terms “alkyl,” “alkenyl,” “alkyne,” “acylic,” “alicyclic group,”        “aryl,” “heteroaryl,” and “heterocyclic group” are as defined        herein.

As used herein, the term “alkyl” includes a straight or branchedsaturated aliphatic hydrocarbon chain having from 1 to 22 carbon atoms,such as, for example, methyl, ethyl, propyl, isopropyl (1-methylethyl),butyl, tert-butyl (1,1-dimethylethyl), and the like. The term “alkyl” or“alkyl groups” also refers to saturated hydrocarbons having one or morecarbon atoms, including straight-chain alkyl groups (e.g., methyl,ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, decyl, etc.),cyclic alkyl groups (or “cycloalkyl” or “alicyclic” or “carbocyclic”groups) (e.g., cyclopropyl, cyclopentyl, cyclohexyl, cycloheptyl,cyclooctyl, etc.), branched-chain alkyl groups (e.g., isopropyl,tert-butyl, sec-butyl, isobutyl, etc.), and alkyl-substituted alkylgroups (e.g., alkyl-substituted cycloalkyl groups andcycloalkyl-substituted alkyl groups).

Unless otherwise specified, the term “alkyl” includes both“unsubstituted alkyls” and “substituted alkyls.” As used herein, theterm “substituted alkyls” refers to alkyl groups having substituentsreplacing one or more hydrogens on one or more carbons of thehydrocarbon backbone. Such substituents may include, for example,alkenyl, alkynyl, halogeno, hydroxyl, alkylcarbonyloxy, arylcarbonyloxy,alkoxycarbonyloxy, aryloxy, aryloxycarbonyloxy, carboxylate,alkylcarbonyl, arylcarbonyl, alkoxycarbonyl, aminocarbonyl,alkylaminocarbonyl, dialkylaminocarbonyl, alkylthiocarbonyl, alkoxyl,phosphate, phosphonato, phosphinato, cyano, amino (including alkylamino, dialkylamino, arylamino, diarylamino, and alkylarylamino),acylamino (including alkylcarbonylamino, arylcarbonylamino, carbamoyland ureido), imino, sulfhydryl, alkylthio, arylthio, thiocarboxylate,sulfates, alkylsulfinyl, sulfonates, sulfamoyl, sulfonamido, nitro,trifluoromethyl, cyano, azido, heterocyclic, alkylaryl, or aromatic(including heteroaromatic) groups.

The term “alkenyl” includes an unsaturated aliphatic hydrocarbon chainhaving from 2 to 12 carbon atoms, such as, for example, ethenyl,1-propenyl, 2-propenyl, 1-butenyl, 2-methyl-1-propenyl, and the like.The alkyl or alkenyl can be terminally substituted with a heteroatom,such as, for example, a nitrogen, sulfur, or oxygen atom, forming anaminoalkyl, oxyalkyl, or thioalkyl, for example, aminomethyl, thioethyl,oxypropyl, and the like. Similarly, the above alkyl or alkenyl can beinterrupted in the chain by a heteroatom forming an alkylaminoalkyl,alkylthioalkyl, or alkoxyalkyl, for example, methylaminoethyl,ethylthiopropyl, methoxymethyl, and the like.

Further, as used herein the term “alicyclic” includes any cyclichydrocarbyl containing from 3 to 8 carbon atoms. Examples of suitablealicyclic groups include cyclopropanyl, cyclobutanyl, cyclopentanyl,etc. The term “heterocyclic” includes any closed ring structuresanalogous to carbocyclic groups in which one or more of the carbon atomsin the ring is an element other than carbon (heteroatom), for example, anitrogen, sulfur, or oxygen atom. Heterocyclic groups may be saturatedor unsaturated. Examples of suitable heterocyclic groups include forexample, aziridine, ethylene oxide (epoxides, oxiranes), thiirane(episulfides), dioxirane, azetidine, oxetane, thietane, dioxetane,dithietane, dithiete, azolidine, pyrrolidine, pyrroline, oxolane,dihydrofuran, and furan. Additional examples of suitable heterocyclicgroups include groups derived from tetrahydrofurans, furans, thiophenes,pyrrolidines, piperidines, pyridines, pyrrols, picoline, coumaline, etc.

In some embodiments, alkyl, alkenyl, alicyclic groups, and heterocyclicgroups can be unsubstituted or substituted by, for example, aryl,heteroaryl, C₁₋₄ alkyl, C₁₋₄ alkenyl, C₁₋₄ alkoxy, amino, carboxy, halo,nitro, cyano, —SO₃H, phosphono, or hydroxy. When alkyl, alkenyl,alicyclic group, or heterocyclic group is substituted, preferably thesubstitution is C₁₋₄ alkyl, halo, nitro, amido, hydroxy, carboxy,sulpho, or phosphono. In one embodiment, R includes alkyl substitutedwith hydroxy. The term “aryl” includes aromatic hydrocarbyl, includingfused aromatic rings, such as, for example, phenyl and naphthyl. Theterm “heteroaryl” includes heterocyclic aromatic derivatives having atleast one heteroatom such as, for example, nitrogen, oxygen, phosphorus,or sulfur, and includes, for example, furyl, pyrrolyl, thienyl,oxazolyl, pyridyl, imidazolyl, thiazolyl, isoxazolyl, pyrazolyl,isothiazolyl, etc. The term “heteroaryl” also includes fused rings inwhich at least one ring is aromatic, such as, for example, indolyl,purinyl, benzofuryl, etc.

In some embodiments, aryl and heteroaryl groups can be unsubstituted orsubstituted on the ring by, for example, aryl, heteroaryl, alkyl,alkenyl, alkoxy, amino, carboxy, halo, nitro, cyano, —SO₃H, phosphono,or hydroxy. When aryl, aralkyl, or heteroaryl is substituted, preferablythe substitution is C₁₋₄ alkyl, halo, nitro, amido, hydroxy, carboxy,sulpho, or phosphono. In one embodiment, R includes aryl substitutedwith C₁₋₄ alkyl.

Peracids suitable for use include any peroxycarboxylic acids, includingvarying lengths of peroxycarboxylic and percarboxylic acids (e.g. C1-22)that can be prepared from the acid-catalyzed equilibrium reactionbetween a carboxylic acid described above and hydrogen peroxide. Aperoxycarboxylic acid can also be prepared by the auto-oxidation ofaldehydes or by the reaction of hydrogen peroxide with an acid chloride,acid hydride, carboxylic acid anhydride, or sodium alcoholate.Alternatively, peracids can be prepared through non-equilibriumreactions, which may be generated for use in situ, such as the methodsdisclosed in U.S. patent application Ser. Nos. 13/331,304 and 13/331,486each titled “In Situ Generation of Peroxycarboxylic Acids at AlkalinepH, and Methods of Use Thereof,” which are incorporated herein byreference. Preferably a composition of the invention includesperoxyacetic acid, peroxyoctanoic acid, peroxypropionic acid,peroxylactic acid, peroxyheptanoic acid, peroxyoctanoic acid and/orperoxynonanoic acid.

In some embodiments, a peroxycarboxylic acid includes at least onewater-soluble peroxycarboxylic acid in which R includes alkyl of 1-22carbon atoms. For example, in one embodiment, a peroxycarboxylic acidincludes peroxyacetic acid. In another embodiment, a peroxycarboxylicacid has R that is an alkyl of 1-22 carbon atoms substituted withhydroxy. Methods of preparing peroxyacetic acid are known to those ofskill in the art including those disclosed in U.S. Pat. No. 2,833,813,which is herein incorporated herein by reference.

In another embodiment, a sulfoperoxycarboxylic acid has the followingformula:

wherein R₁ is hydrogen, or a substituted or unsubstituted alkyl group;R₂ is a substituted or unsubstituted alkylene group; X is hydrogen, acationic group, or an ester forming moiety; or salts or esters thereof.In additional embodiments, a sulfoperoxycarboxylic acid is combined witha single or mixed peroxycarboxylic acid composition, such as asulfoperoxycarboxylic acid with peroxyacetic acid and peroxyoctanoicacid. (PSOA/POOA/POAA).

In other embodiments, a mixed peracid is employed, such as aperoxycarboxylic acid including at least one peroxycarboxylic acid oflimited water solubility in which R includes alkyl of 5-22 carbon atomsand at least one water-soluble peroxycarboxylic acid in which R includesalkyl of 1-4 carbon atoms. For example, in one embodiment, aperoxycarboxylic acid includes peroxyacetic acid and at least one otherperoxycarboxylic acid such as those named above. Preferably acomposition of the invention includes peroxyacetic acid andperoxyoctanoic acid. Other combinations of mixed peracids are wellsuited for use in the current invention.

In another embodiment, a mixture of peracetic acid and peroctanoic acidis used to treat a water source, such as disclosed in U.S. Pat. No.5,314,687 which is herein incorporated by reference in its entirety. Inan aspect, the peracid mixture is a hydrophilic peracetic acid and ahydrophobic peroctanoic acid, providing antimicrobial synergy. In anaspect, the synergy of a mixed peracid system allows the use of lowerdosages of the peracids.

In another embodiment, a tertiary peracid mixture composition, such asperoxysulfonated oleic acid, peracetic acid and peroctanoic acid areused to treat a water source, such as disclosed in U.S. PatentPublication No. 2010/00021557 which is incorporated herein by referencein its entirety. A combination of the three peracids providessignificant antimicrobial synergy providing an efficient antimicrobialcomposition for the water treatment methods according to the invention.In addition, it is thought the high acidity built in the compositionassists in removing chemical contaminants from the water (e.g. sulfiteand sulfide species).

Advantageously, a combination of peroxycarboxylic acids provides acomposition with desirable antimicrobial activity in the presence ofhigh organic soil loads. The mixed peroxycarboxylic acid compositionsoften provide synergistic micro efficacy. Accordingly, compositions ofthe invention can include a peroxycarboxylic acid, or mixtures thereof.

Various commercial formulations of peracids are available, including forexample, peracetic acid (15%) available as EnviroSan (EcolabInc., St.Paul Minn.). Most commercial peracid solutions state a specificpercarboxylic acid concentration without reference to the other chemicalcomponents in a use solution. However, it should be understood thatcommercial products, such as peracetic acid, will also contain thecorresponding carboxylic acid (e.g. acetic acid), hydrogen peroxide andwater.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentcompositions. In some embodiments, the C₁-C₂₂ percarboxylic acid is aC₂-C₂₀ percarboxylic acid. In other embodiments, the C₁-C₂₂percarboxylic is a C₁, C₂, C₃, C₄, C₅, C₆, C₇, C₈, C₉, C₁₀, C₁₁, C₁₂,C₁₃, C₁₄, C₁₅, C₁₆, C₁₇, C₁₈, C₁₉, C₂₀, C₂₁, or C₂₂ carboxylic acid. Instill other embodiments, the C₁-C₂₂ percarboxylic acid comprisesperoxyacetic acid, peroxyoctanoic acid and/or peroxysulfonated oleicacid.

The C₁-C₂₂ percarboxylic acid can be used at any suitable concentration.In some embodiments, the C₁-C₂₂ percarboxylic acid has a concentrationfrom about 1 wt-% to about 40 wt-%. In other embodiments, the C₁-C₂₂percarboxylic acid has a concentration from about 1 wt-% to about 20wt-%. In still other embodiments, the C₁-C₂₂ percarboxylic acid has aconcentration at about 1 wt-%, 2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7wt-%, 8 wt-%, 9 wt-%, 10 wt-%, 11 wt-%, 12 wt-%, 13 wt-%, 14 wt-%, 15wt-%, 16 wt-%, 17 wt-%, 18 wt-%, 19 wt-%, 20 wt-%, 25 wt-%, 30 wt-%, 35wt-%, or 40 wt-%.

Hydrogen Peroxide

The present invention includes the use of hydrogen peroxide. Hydrogenperoxide, H₂O₂, provides the advantages of having a high ratio of activeoxygen because of its low molecular weight (34.014 g/mole) and beingcompatible with numerous substances that can be treated by methods ofthe invention because it is a weakly acidic, clear, and colorlessliquid. Another advantage of hydrogen peroxide is that it decomposesinto water and oxygen. It is advantageous to have these decompositionproducts because they are generally compatible with substances beingtreated. For example, the decomposition products are generallycompatible with metallic substance (e.g., substantially noncorrosive)and are generally innocuous to incidental contact and areenvironmentally friendly.

In one aspect of the invention, hydrogen peroxide is initially in anantimicrobial peracid composition in an amount effective for maintainingan equilibrium between a carboxylic acid, hydrogen peroxide, a solventsuch as water, and a peracid. The amount of hydrogen peroxide should notexceed an amount that would adversely affect the antimicrobial activityof a composition of the invention. In further aspects of the invention,hydrogen peroxide concentration is significantly reduced within anantimicrobial peracid composition, preferably containing hydrogenperoxide at a concentration as close to zero as possible. That is, theconcentration of hydrogen peroxide is minimized, through the use of aselected catalase or peroxidase enzymes according to the invention. Infurther aspects, the concentration of hydrogen peroxide is reducedand/or eliminated as a result of distilled equilibrium peracidcompositions, other catalysts for hydrogen peroxide decomposition (e.g.biomimetic complexes) and/or the use of anionic perhydrolysis of esters(e.g. triacetin) to obtain peracids with very low hydrogen peroxide.

In some embodiments, an advantage of minimizing the concentration ofhydrogen peroxide is that antimicrobial activity of a composition of theinvention is improved as compared to conventional equilibrium peracidcompositions. Without being limited to a particular theory of theinvention, significant improvements in antimicrobial efficacy resultfrom enhanced peracid stability from the reduced hydrogen peroxideconcentration in use solution.

The hydrogen peroxide can be used at any suitable concentration. In someembodiments, the hydrogen peroxide has a concentration from about 0.5wt-% to about 10 wt-%. In other embodiments, the hydrogen peroxide has aconcentration from about 1 wt-% to about 2 wt-%. In still otherembodiments, the hydrogen peroxide has a concentration at about 0.5wt-%, 1 wt-%, 2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9wt-%, or 10 wt-%. In yet other embodiments, the hydrogen peroxide has aconcentration at about 1 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4 wt-%,1.5 wt-%, 1.6 wt-%, 1.7 wt-%, 1.8 wt-%, 1.9 wt-%, or 2 wt-%.

In some embodiments, the C₁-C₂₂ carboxylic acid is acetic acid and theC₁-C₂₂ percarboxylic acid is peracetic acid. In other embodiments, theC₁-C₂₂ carboxylic acid, e.g., acetic acid, has a concentration of about70 wt-%, the C₁-C₂₂ percarboxylic acid, e.g., peracetic acid, has aconcentration of about 15 wt-%, and the hydrogen peroxide has aconcentration of at least about 1 wt-%.

Stabilizing Agents

In some aspects, more than one type of stabilizer is used in thecompositions. In some embodiments, at least one stabilizer is aphosphonic acid or a derivative thereof. Without wishing to be bound byany particular theory, it is thought that in addition to functioning asa stabilizer through the chelating of transition metal ions, phosphonicacid based stabilizers such as HEDP, also act as an acid catalyst andaid in the formation of the peroxycarboxylic acid from the correspondingcarboxylic acid and hydrogen peroxide. In some embodiments, a pyridinecarboxylic acid based stabilizer is used as a second stabilizer.Pyridine carboxylic acids such as 2,6-pyridinedicarboxylic acid (DPA),are well known chelators for metal ions. It is thought that by using twodifferent types of stabilizers, the transition metals responsible forthe catalytic decomposition of peroxycarboxylic acids are moreefficiently deactivated by forming a more stable complex(es) involvingboth chelators.

Any suitable first stabilizing agent can be used in the presentcompositions. In some embodiments, the first stabilizing agent is apicolinic acid, or a salt thereof. In other embodiments, the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.The first stabilizing agent can be used at any suitable concentration.In some embodiments, the first stabilizing agent has a concentrationfrom about 0.005 wt-% to about 5 wt-%. In other embodiments, the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%. In still other embodiments, the first stabilizing agent has aconcentration at about 0.005 wt-%, 0.01 wt-%, 0.1 wt-%, 1 wt-%, 2 wt-%,3 wt-%, 4 wt-%, or 5 wt-%. In yet other embodiments, the firststabilizing agent has a concentration at about 0.05 wt-%, 0.06 wt-%,0.07 wt-%, 0.08 wt-%, 0.09 wt-%, 0.10 wt-%, 0.11 wt-%, 0.12 wt-%, 0.13wt-%, 0.14 wt-%, or 0.15 wt-%.

Any suitable second stabilizing agent can be used in the presentcompositions. In some embodiments, the second stabilizing agent is1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), or a salt thereof.The second stabilizing agent can be used at any suitable concentration.In some embodiments, the second stabilizing agent has a concentrationfrom about 0.1 wt-% to about 10 wt-%, e.g., 0.1 wt-%, 0.5 wt-%, 1 wt-%,2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%, or 10wt-%. In other embodiments, the second stabilizing agent has aconcentration from about 0.5 wt-% to about 5 wt-%, e.g., 0.5 wt-%, 1wt-%, 1.5 wt-%, 2 wt-%, 2.5 wt-%, 3 wt-%, 3.5 wt-%, 4 wt-%, 4.5 wt-% or5 wt-%. In still other embodiments, the second stabilizing agent has aconcentration from about 0.6 wt-% to about 1.8 wt-%, e.g., 0.6 wt-%, 0.7wt-%, 0.8 wt-%, 0.9 wt-%, 1.0 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4wt-%, 1.5 wt-%, 1.6 wt-%, 1.7 wt-%, 1.8 wt-%.

In some embodiments, the present composition can further comprise asubstance that aids solubilization of the first and/or secondstabilizing agent(s). Exemplary substances that can aid solubilizationof the first and/or second stabilizing agent(s) include hydrotropes suchas sodium xylene sulfonate, sodium cumene sulfonates, and surfactants,such as anionic surfactants and noinionic surfactants.

In some embodiments, the first stabilizing agent is a2,6-pyridinedicarboxylic acid, or a salt thereof, and the secondstabilizing agent is HEDP, or a salt thereof. In other embodiments, thefirst and second stabilizing agents act synergistically to delay orprevent the composition from meeting its self-accelerating decompositiontemperature (SADT). SADT refers to the lowest temperature at whichself-accelerating decomposition may occur with a composition. In someembodiments, SADT refers to the lowest temperature at whichself-accelerating decomposition may occur under the commercialpackaging, storage, transportation and/or use condition(s). SADT can beestimated, calculated, predicted and/or measured by any suitablemethods. For example, SADT can be estimated, or measured directly by oneof 3 methods (H1,H2 and H4) recommended by UN Committee for theTransportation of Dangerous Goods in “Recommendations on the Transportof Dangerous Goods, Model Regulations” (Rev.17) ST/SG/AC.10/1/Rev.17.For example, the methodology disclosed in Malow and Wehrstedt, J. HazardMater., 120(1-3):21-4 (2005) can be used.

The present compositions can retain any suitable level or percentage ofthe C₁-C₂₂ percarboxylic acid activity under the usual packaging,storage, transportation and/or use condition(s). In some embodiments,the present compositions retain at least about 80% of the C₁-C₂₂percarboxylic acid activity after storage of about 30 days at about 50°C. Preferably, the present compositions retain at least about 85%, 90%or higher percentage of the C₁-C₂₂ percarboxylic acid activity afterstorage of about 30 days at about 50° C.

Additional Optional Materials

The present compositions can optionally include additional ingredientsto enhance the composition for water treatment according to theinvention, including for example, friction reducers, viscosity enhancersand the like. Additional optional functional ingredients may include forexample, peracid stabilizers, emulsifiers, corrosion inhibitors and/ordescaling agents (i.e. scale inhibitors), surfactants and/or additionalantimicrobial agents for enhanced efficacy (e.g. mixed peracids,biocides), antifoaming agents, acidulants (e.g. strong mineral acids),additional carboxylic acids, and the like. In an embodiment, noadditional functional ingredients are employed.

Friction Reducers

Friction reducers are used in water or other water-based fluids used inhydraulic fracturing treatments for subterranean well formations inorder to improve permeability of the desired gas and/or oil beingrecovered from the fluid-conductive cracks or pathways created throughthe fracking process. The friction reducers allow the water to be pumpedinto the formations more quickly. Various polymer additives have beenwidely used as friction reducers to enhance or modify thecharacteristics of the aqueous fluids used in well drilling, recoveryand production applications.

Examples of commonly used friction reducers include polyacrylamidepolymers and copolymers. In an aspect, additional suitable frictionreducers may include acrylamide-derived polymers and copolymers, such aspolyacrylamide (sometime abbreviated as PAM), acrylamide-acrylate(acrylic acid) copolymers, acrylic acid-methacrylamide copolymers,partially hydrolyzed polyacrylamide copolymers (PHPA), partiallyhydrolyzed polymethacrylamide, acrylamide-methyl-propane sulfonatecopolymers (AMPS) and the like. Various derivatives of such polymers andcopolymers, e.g., quaternary amine salts, hydrolyzed versions, and thelike, should be understood to be included with the polymers andcopolymers described herein.

Friction reducers are combined with water and/or other aqueous fluids,which in combination are often referred to as “slick water” fluids.Slick water fluids have reduced frictional drag and beneficial flowcharacteristics which enable the pumping of the aqueous fluids intovarious gas- and/or oil-producing areas, including for example forfracturing.

In an aspect of the invention, a friction reducer is present in a usesolution in an amount between about 100 ppm to 1,000 ppm. In a furtheraspect, a friction reducer is present in a use solution in an amount ofat least about 0.01 wt-% to about 10 wt-%, preferably at least about0.01 wt-% to about 5 wt-%, preferably at least about 0.01 wt-% to about1 wt-%, more preferably at least about 0.01 wt-% to about 0.5 wt-%, andstill more preferably at least about 0.01 wt-% to about 0.1 wt-%.Beneficially, the compositions and methods of the invention do notnegatively interfere with friction reducers included in an aqueoussolution. Without being limited to a particular theory of the invention,it is thought that the reduction and/or elimination of the oxidanthydrogen peroxide from the peracid composition promotes the stabilityand efficacy of any variation in the amount of friction reducer presentin a use solution.

Viscosity Enhancers

Viscosity enhancers are additional polymers used in water or otherwater-based fluids used in hydraulic fracturing treatments to provideviscosity enhancement. Natural and/or synthetic viscosity-increasingpolymers may be employed in compositions and methods according to theinvention. Viscosity enhancers may also be referred to as gelling agentsand examples include guar, xanthan, cellulose derivatives andpolyacrylamide and polyacrylate polymers and copolymers, and the like.

In an aspect of the invention, a viscosity enhancer is present in a usesolution in an amount between about 100 ppm to 1,000 ppm. In a furtheraspect, a viscosity enhancer is present in a use solution in an amountof at least about 0.01 wt-% to about 10 wt-%, preferably at least about0.01 wt-% to about 5 wt-%, preferably at least about 0.01 wt-% to about1 wt-% at least about 0.01 wt-% to about 2 wt-%, preferably at leastabout 0.01 wt-% to about 1 wt-%, preferably at least about 0.01 wt-% toabout 0.5 wt-%. Beneficially, the compositions and methods of theinvention do not negatively interfere with viscosity enhancer includedin an aqueous solution. Without being limited to a particular theory ofthe invention, it is believed the reduction and/or elimination of theoxidant hydrogen peroxide from the peracid composition promotes thestability and efficacy of any variation in the amount of viscosityenhancer present in a use solution.

Corrosion Inhibitors

Corrosion inhibitors are additional molecules used in oil and gasrecovery operations. Corrosion inhibitors that may be employed in thepresent disclosure include the exemplary corrosion inhibitors disclosedin U.S. Pat. No. 5,965,785, U.S. patent application Ser. No. 12/263,904,GB Pat. No. 1,198,734, WO/03/006581, WO04/044266, and WO08/005058, eachincorporated herein by reference in their entireties.

In an aspect of the invention, a corrosion inhibitor is present in a usesolution in an amount between about 100 ppm to 1,000 ppm. In a furtheraspect, a corrosion inhibitor is present in a use solution in an amountof at least about 0.0001 wt-% to about 10 wt-%, preferably at leastabout 0.0001 wt-% to about 5 wt-%, preferably at least about 0.0001 wt-%to about 1 wt-%, preferably at least about 0.0001 wt-% to about 0.1wt-%, and still more preferably at least about 0.0001 wt-% to about 0.05wt-%. Beneficially, the compositions and methods of the invention do notnegatively interfere with corrosion inhibitor included in an aqueoussolution. Without being limited to a particular theory of the invention,it is believed the reduction and/or elimination of the oxidant hydrogenperoxide from the peracid composition promotes the stability andefficacy of any variation in the amount of corrosion inhibitor presentin a use solution.

Scale Inhibitors

Scale inhibitors are additional molecules used in oil and gas recoveryoperations. Common scale inhibitors that may be employed in these typesof applications include polymers and co-polymers, phosphates, phosphateesters and the like.

In an aspect of the invention, a scale inhibitor is present in a usesolution in an amount between about 100 ppm to 1,000 ppm. In a furtheraspect, a scale inhibitor is present in a use solution in an amount ofat least about 0.0001 wt-% to about 10 wt-%, at least about 0.0001 wt-%to about 1 wt-%, preferably at least about 0.0001 wt-% to about 0.1wt-%, preferably at least about 0.0001 wt-% to about 0.05 wt-%.Beneficially, the compositions and methods of the invention do notnegatively interfere with scale inhibitor included in an aqueoussolution. Without being limited to a particular theory of the invention,it is thought that the reduction and/or elimination of the oxidanthydrogen peroxide from the peracid composition promotes the stabilityand efficacy of any variation in the amount of scale inhibitor presentin a use solution.

Additional Antimicrobial Agents

Additional antimicrobial agents may be included in the compositionsand/or methods of the invention for enhanced antimicrobial efficacy. Inaddition to the use of peracid compositions, additional antimicrobialagents and biocides may be employed. Additional biocides may include,for example, a quaternary ammonium compound as disclosed in U.S. Pat.No. 6,627,657, which is incorporated herein by reference in itsentirety. Beneficially, the presence of the quaternary ammonium compoundprovides both synergistic antimicrobial efficacies with peracids, aswell as maintains long term biocidal efficacy of the compositions.

In another embodiment, the additional biocide may include an oxidizercompatible phosphonium biocide, such as tributyl tetradecyl phosphoniumchloride. The phosphonium biocide provides similar antimicrobialadvantages as the quaternary ammonium compound in combination with theperacids. In addition, the phosphonium biocide is compatible with theanionic polymeric chemicals commonly used in the oil field applications,such as the methods of the fracking disclosed according to theinvention.

Additional antimicrobial and biocide agents may be employed in amountssufficient to provide antimicrobial efficacy, as may vary depending uponthe water source in need of treatment and the contaminants therein. Suchagents may be present in a use solution in an amount of at least about0.1 wt-% to about 50 wt-%, preferably at least about 0.1 wt-% to about20 wt-%, more preferably from about 0.1 wt-% to about 10 wt-%.

Acidulants

Acidulants may be included as additional functional ingredients in acomposition according to the invention. In an aspect, a strong mineralacid such as nitric acid or sulfuric acid can be used to treat watersources, as disclosed in U.S. Pat. No. 4,587,264, which is incorporatedherein by reference in its entirety. The combined use of a strongmineral acid with the peracid composition provides enhancedantimicrobial efficacy as a result of the acidity assisting in removingchemical contaminants within the water source (e.g. sulfite and sulfidespecies). In addition, some strong mineral acids, such as nitric acid,provide a further benefit of reducing the risk of corrosion towardmetals contacted by the peracid compositions according to the invention.Exemplary products are commercially available from Enviro Tech ChemicalServices, Inc. (Reflex brand) and from Solvay Chemicals (Proxitane® NTbrand).

Acidulants may be employed in amounts sufficient to provide the intendedantimicrobial efficacy and/or anticorrosion benefits, as may varydepending upon the water source in need of treatment and thecontaminants therein. Such agents may be present in a use solution in anamount of at least about 0.1 wt-% to about 50 wt-%, preferably at leastabout 0.1 wt-% to about 20 wt-%, more preferably from about 0.1 wt-% toabout 10 wt-%.

Catalase and Peroxidase Enzyme

In an aspect of the invention, a catalase or peroxidase enzyme is usedto reduce and/or eliminate the concentration of hydrogen peroxide in anantimicrobial peracid composition. The enzymes catalyze thedecomposition of hydrogen peroxide to water and oxygen. Beneficially,the reduction and/or elimination of hydrogen peroxide (strong oxidizer)results in other additives for a water treatment source (e.g. watersource) not being degraded or rendered incompatible. Various additivesused to enhance or modify the characteristics of the aqueous fluids usedin well drilling, recovery and production applications are at risk ofdegradation by the oxidizing effects of hydrogen peroxide. These mayinclude for example, friction reducers and viscosity enhancers used incommercial well drilling, well completion and stimulation, or productionapplications.

Various sources of catalase enzymes may be employed according to theinvention, including: animal sources such as bovine catalase isolatedfrom beef livers; fungal catalases isolated from fungi includingPenicillium chrysogenum, Penicillium notatum, and Aspergillus niger;plant sources; bacterial sources such as Staphylcoccus aureus, andgenetic variations and modifications thereof. In an aspect of theinvention, fungal catalases are utilized to reduce the hydrogen peroxidecontent of a peracid composition. Catalases are commercially availablein various forms, including liquid and spray dried forms. Commerciallyavailable catalase includes both the active enzyme as well as additionalingredients to enhance the stability of the enzyme. Some exemplarycommercially available catalase enzymes include Genencor CA-100 andCA-400, as well as Mitsubishi Gas and Chemical (MGC) ASC super G and ASCsuper 200, and Optimase CA 400L from Genecor International. Additionaldescription of suitable catalase enzymes are disclosed and hereinincorporated by reference in its entirety from U.S. Patent PublicationNo. 2009/0269324.

In an aspect of the invention, catalase enzymes have a high ability todecompose hydrogen peroxide. Beneficially, the reduction or eliminationof hydrogen peroxide from oxidizing compositions obviates the variousdetriments caused by oxidizing agents. In particular, the use ofcatalase with the peracids compositions provides enhanced antimicrobialbenefits without causing the damage associated with conventionaloxidizing agents (e.g. peracetic acid, hypochlorite or hypochlorousacid, and/or chlorine dioxide), such as corrosion.

Peroxidase enzymes may also be employed to decompose hydrogen peroxidefrom a peracid composition. Although peroxidase enzymes primarilyfunction to enable oxidation of substrates by hydrogen peroxide, theyare also suitable for effectively lowering hydrogen peroxide to peracidratios in compositions. Various sources of peroxidase enzymes may beemployed according to the invention, including for example animalsources, fungal peroxidases, and genetic variations and modificationsthereof. Peroxidases are commercially available in various forms,including liquid and spray dried forms. Commercially availableperoxidases include both the active enzyme as well as additionalingredients to enhance the stability of the enzyme.

In some embodiments, the catalase or peroxidase enzyme is able todegrade at least about 50% of the initial concentration of hydrogenperoxide in a peracid composition. Preferably, the enzyme is provided insufficient amount to reduce the hydrogen peroxide concentration of aperacid composition by at least more than about 50%, more preferably atleast about 60%, at least about 70%, at least about 80%, at least about90%. In some embodiments, the enzyme reduces the hydrogen peroxideconcentration of a peracid composition by more than 90%.

In an aspect of the invention, the enzymes are suitable for use and havea tolerance to a wide range of temperatures, including the temperaturesranges in water treatment applications which may range from about 0-180°C. A suitable catalase enzyme will maintain at least 50% of its activityunder such storage and/or application temperatures for at least about 10minutes, preferably for at least about 1 hour.

In a further aspect of the invention, the catalase or peroxidase enzymesdescribed herein have a tolerance to pH ranges found in water treatmentapplications. Acetic acid levels (or other carboxylic acid) in a watertreatment application can widely range in parts per million (ppm) ofacetic or other carboxylic acid. The solutions may have a correspondingrange of pH range from greater than 0 to about 10. A suitable catalaseor peroxidase enzyme will maintain at least about 50% of its activity insuch solutions of acetic or other carboxylic acid over a period of about10 minutes.

In an aspect of the invention, a catalase or peroxidase enzyme ispresent in a use solution of the water treatment and peracid compositionin sufficient amounts to reduce the concentration of hydrogen peroxidefrom the peracid composition by at least 50% within about 10 minutes,preferably within about 5 minutes, preferably within about 2 to 5minutes, more preferably within about 1 minute. The ranges ofconcentration of the enzymes will vary depending upon the amount of timewithin which 50% of the hydrogen peroxide from the peracid compositionis removed. In certain aspects of the invention, a catalase orperoxidase enzyme is present in a use solution composition including thewater source to be treated in amounts between about 1 ppm and about1,000 ppm, preferably between about 5 ppm and 500 ppm, and morepreferably between about 10 ppm and about 100 ppm.

Uses of the Present Compositions

In another aspect, the present invention is directed to a method forstoring a percarboxylic acid containing composition, which methodcomprises storing the above compositions, wherein said compositionretains at least about 80% of the C₁-C₂₂ percarboxylic acid activityafter storage for any suitable time under any suitable conditions, e.g.,retaining at least about 80% of the C₁-C₂₂ percarboxylic acid activityafter storage of about 30 days at about 50° C. Preferably, the presentcompositions retain at least about 85%, 90% or higher of the C₁-C₂₂percarboxylic acid activity after storage of about 30 days at about 50°C.

In still another aspect, the present invention is directed to a methodfor transporting a percarboxylic acid containing composition, whichmethod comprises transporting the above compositions under ambientconditions, preferably in bulk e.g., 1,000 gallons and above, whereinthe SADT of said composition is at least 45° C. during transportation.Preferably, the SADT of said composition is higher than at least 50° C.,55° C., 60° C. 65° C. or 70° C.

In yet another aspect, the present invention is directed to a method fortreating water, which method comprises providing the above compositionsto a water source in need of treatment to form a treated water source,wherein said treated water source comprises from about 1 ppm to about1,000 ppm of said C₁-C₂₂ percarboxylic acid.

The present methods can be used to treat any suitable or desirable watersources. For example, the present methods can be used to treat freshwater, pond water, sea water, produced water and a combination thereof.In some embodiments, the water source comprises at least about 1 wt-%produced water. In other embodiments, the water source comprises atleast about 1 wt-%, 2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8wt-%, 9 wt-%, or 10 wt-%, 15 wt-%, 20 wt-%, 25 wt-%, 30 wt-% or moreproduced water.

The treated water source can comprise any suitable concentration of theC₁-C₂₂ percarboxylic acid. In some embodiments, the treated water sourcecomprises from about 10 ppm to about 200 ppm of the C₁-C₂₂ percarboxylicacid. In other embodiments, the treated water source comprises about 1ppm, 10 ppm, 100 ppm, 200 ppm, 300 ppm, 400 ppm, 500 ppm, 600 ppm, 700ppm, 800 ppm, 900 ppm or1,000 ppm of the C₁-C₂₂ percarboxylic acid. Thepresent methods can be used to treat any suitable or desirable watersources. In another example, the present methods can be used to treatfresh water, pond water, sea water, produced water and a combinationthereof. In some embodiments, the water source comprises at least about1 wt-% produced water. In other embodiments, the water source comprisesat least about 1 wt-%, 2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8wt-%, 9 wt-%, or 10 wt-%, 15 wt-%, 20 wt-%, 25 wt-%, 30 wt-% or moreproduced water.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentmethods. For example, peroxyacetic acid, peroxyoctanoic acid and/orperoxysulfonated oleic acid can be used. In some embodiments, acombination of peroxyacetic acid, peroxyoctanoic acid andperoxysulfonated oleic acid is used.

The treated water source can comprise any suitable concentration of thehydrogen peroxide. In some embodiments, the treated water sourcecomprises from about 1 ppm to about 15 ppm of the hydrogen peroxide. Inother embodiments, the treated water source comprises about 1 ppm, 2ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9 ppm, 10 ppm, 11 ppm, 12ppm, 13 ppm, 14 ppm, or 15 ppm of the hydrogen peroxide.

The treated water source can retain any suitable concentration and/orpercentage of the initial C₁-C₂₂ percarboxylic acid activity in thetreated water source for any suitable time period after the treatedwater source is formed. In some embodiments, the treated water sourceretains at least about 60%, 65%, 70%, 75%, 80%, 85% or 90% of theinitial C₁-C₂₂ percarboxylic acid activity in the treated water sourcefor a suitable time after the treated water source is formed. In otherembodiments, the treated water source retains at least about 60%, 65%,70%, 75%, 80%, 85% or 90% of the initial C₁-C₂₂ percarboxylic acidactivity in the treated water source for at least 15 minutes after thetreated water source is formed.

In some embodiments, the level of a microorganism, if present in thewater source, is stabilized or reduced by the present methods. Forexample, at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, or 90% or moreof the microorganism, if present in the water source, is killed,destroyed, removed and/or inactivated by the present methods.

In some embodiments, the antimicrobial efficacy of the composition usedin the present methods on the treated water source is comparable toantimicrobial effect of a water source that does not contain producedwater. In other embodiments, the treated water source reduces corrosioncaused by hydrogen peroxide and reduces microbial-induced corrosion, andthe composition used in the present methods does not substantiallyinterfere with a friction reducer, a viscosity enhancer, otherfunctional ingredients present in the treated water source, or acombination thereof.

In some embodiments, the present methods can comprise adding aperoxidase or a catalase to further reduce the hydrogen peroxide levelin the treated water source. The peroxidase or catalase can be added inany suitable manner. In some embodiments, the peroxidase or catalase canbe added to the water source before a composition used in the presentmethods is provided to the water source. In other embodiments, thepresent compositions can be diluted into a suitable intermediate volume,and the peroxidase or catalase can be added to the diluted, intermediatevolume. Thereafter, the diluted, intermediate volume, which contains theperoxidase or catalase, can be added to the water source. Any suitableperoxidase or catalase, including the ones described below, can be usedin the present methods.

In some embodiments, the present methods can further comprise directingthe treated water source into a subterranean environment or disposing ofthe treated water source.

In some embodiments, the water source treated by the present methodsdoes not comprise reuse water, the treated water source comprises fromabout 10 ppm to about 20 ppm of the C₁-C₂₂ percarboxylic acid and fromabout 1 ppm to about 2 ppm of hydrogen peroxide and the treated watersource does not comprise a friction reducer and/or a rheology modifier.

In some embodiments, the water source treated by the present methods isa blended water source that comprises about 80 wt-% fresh water or pondwater and about 20 wt-% of reuse water, the treated water sourcecomprises from about 25 ppm to about 35 ppm of the C₁-C₂₂ percarboxylicacid and from about 2 ppm to about 3 ppm of hydrogen peroxide andcatalase, the treated water source does not comprise a friction reducerand/or a rheology modifier, and the treated water source is formedbefore reaching a blending tub.

In some embodiments, the water source treated by the present methods isa blended water source that comprises about 80 wt-% fresh water or pondwater and about 20 wt-% of reuse water, the treated water sourcecomprises from about 25 ppm to about 35 ppm of the C₁-C₂₂ percarboxylicacid and from about 2 ppm to about 3 ppm of hydrogen peroxide andcatalase, the treated water source comprises a friction reducer and/or arheology modifier, and the treated water source is formed in a blendingtub.

In some embodiments, the treated water source comprises from about 30ppm or less of the C₁-C₂₂ percarboxylic acid and about 0.5 ppm or lessof the hydrogen peroxide, the treated water source comprises a frictionreducer and/or a rheology modifier, and the treated water source isdirected into or is at a subterranean environment.

In some aspects, the methods disclosed for water treatment in oil andgas recovery provide effective antimicrobial efficacy withoutdeleterious interaction with functional agents, including for examplefriction reducers. In a further aspect, the methods for water treatmentprovide increased antimicrobial efficacy compared to the use of theantimicrobial peracids alone. In a still further aspect, the methods ofuse result in the disposal of cleaner water with low numbers ofmicroorganisms. In yet a further aspect of the methods of the invention,the reduction and/or elimination of H₂O₂ from the peracid compositionsminimizes the negative effects of the oxidant H₂O₂. Still further, themethods of the invention reduce the volume expansion within sealedsystems used in oil and gas recovery methods, as a result of thereduction and/or elimination of H₂O₂ from the systems.

Use in Water Treatment

The treated peracid compositions can be used for a variety of industrialapplications, e.g., to reduce microbial or viral populations on asurface or object or in a body or stream of water. In some aspects, theinvention includes methods of using the treated peracid compositions toprevent biological fouling in various industrial processes andindustries, including oil and gas operations, to control microorganismgrowth, eliminate microbial contamination, limit or prevent biologicalfouling in liquid systems, process waters or on the surfaces ofequipment that come in contact with such liquid systems. As referred toherein, microbial contamination can occur in various industrial liquidsystems including, but not limited to, air-borne contamination, watermake-up, process leaks and improperly cleaned equipment. In anotheraspect, peracid and catalase compositions (or other treated peracidcompositions having low to substantially no hydrogen peroxide) are usedto control the growth of microorganisms in water used in various oil andgas operations. In a further aspect, the compositions are suitable forincorporating into fracturing fluids to control or eliminatemicroorganisms.

As used herein for the methods of the invention, treated peracidcompositions can employ a variety of peracid compositions having a lowto substantially no hydrogen peroxide concentration. These treatedperacid compositions include peracid compositions with a catalase orperoxidase enzyme to reduce the hydrogen peroxide to peracid ratioand/or other reduced hydrogen peroxide peracid compositions disclosedherein. In a preferred embodiment peracid and catalase use solutionshaving reduced or substantially no hydrogen peroxide are introduced to awater source in need of treatment.

The methods by which the treated peracid use solutions are introducedinto the aqueous fluids according to the invention are not critical.Introduction of the treated peracid compositions may be carried out in acontinuous or intermittent manner and will depend on the type of waterbeing treated. In some embodiments, the treated peracid compositions areintroduced into an aqueous fluid according to the methods disclosed inU.S. patent application Ser. No. 13/645,671, titled “New Method andArrangement for Feeding Chemicals into a Hydrofracturing Process and Oiland Gas Applications”, which is hereby incorporated by reference in itsentirety.

In an aspect, the treated peracid use solutions are added to waters inneed of treatment prior to the drilling and fracking steps in order torestrict the introduction of microbes into the reservoir and to preventthe microbes from having a negative effect on the integrity of thefluids.

The treatment of source waters (e.g. pond, lake, municipal, etc.) and/orproduced waters is particularly well suited for use according to theinvention.

The treated waters according to the invention can be used for both slickwater fracturing (i.e. using frictions reducers) and/or gel fracturing(i.e. using viscosity enhancers), depending on the type of formationbeing fractured and the type of hydrocarbon expected to be produced. Useof a treated peracid use solution, including a catalase treated peracidcomposition use solution having low to substantially no hydrogenperoxide, is suitable for both slick water fracturing and gelfracturing.

In an aspect, pretreating the peracid peracetic acid (including amixture of acetic acid, hydrogen peroxide and water) with catalasesubstantially removes the hydrogen peroxide with minimal to no impact onthe fracturing fluids and the well itself. In an aspect, the peraceticacid pretreated with catalase allows the formation of gel suitable forgel fracturing, as opposed to untreated peracetic acid/hydrogen peroxidesolutions that do not allow a gel to form under certain conditions. In afurther aspect, the treated peracid use solutions are added to waters inneed of treatment in the subterranean well formations (e.g. introducedthrough a bore hole in a subterranean formation). These methods provideadditional control within the well formation suitable for reducingmicrobial populations already present within the down hole tubing in thewell or within the reservoir itself.

In a still further aspect, the treated peracid use solutions are addedto waters in need of treatment before disposal. In such an aspect, flowback waters (e.g. post fracking) are treated to minimize microbialcontaminations in the waters and to remove solids prior to disposal ofthe water into a subterranean well, reuse in a subsequent fracturingapplication or return of the water into local environmental watersources.

In an aspect, the water source in need of treatment may varysignificantly. For example, the water source may be a freshwater source(e.g. pond water), salt water or brine source, brackish water source,recycled water source, or the like. In an aspect, wherein offshore welldrilling operations are involved, seawater sources are often employed(e.g. saltwater or non-saltwater). Beneficially, the peracidcompositions, with or without catalase, of the invention are suitablefor use with any types of water and provide effective antimicrobialefficiency with any of such water sources.

Large volumes of water are employed according to the invention asrequired in well fluid operations. As a result, in an aspect of theinvention, recycled water sources (e.g. produced waters) are oftenemployed to reduce the amount of a freshwater, pond water or seawatersource required. Recycled or produced water are understood to includenon-potable water sources. The use of such produced waters (incombination with freshwater, pond water or seawater) reduces certaineconomic and/or environmental constraints. In an aspect of theinvention, thousands to millions of gallons of water may be employed andthe combination of produced water with fresh water sources providessignificant economic and environmental advantages. In an aspect of theinvention, as much produced water as practical is employed. In anembodiment at least 1% produced water is employed, preferably at least5% produced water is employed, preferably at least 10% produced water isemployed, preferably at least 20% produced water is employed, or morepreferably more than 20% produced water is employed.

In an aspect of the invention, the method includes a pretreatment step,wherein the peracid composition is treated with a catalase enzyme toreduce the hydrogen peroxide concentration in a use solution. Thepretreatment step occurs prior to combining the peracid antimicrobialcomposition and/or catalase to a water source in need of treatment. Inan aspect of the invention, the pretreatment may occur within a fewminutes to hours before addition to a water source. Preferably, acommercial peracid formulation is employed (e.g. peracetic acid).Thereafter, the peracid and catalase composition use solution may bediluted to obtain the desired peracetic acid concentrations, with lowand/or no hydrogen peroxide concentration.

According to embodiments of the invention, a sufficient amount of thepretreated peracid use solution composition, with or without catalase,is added to the aqueous water source in need of treatment to provide thedesired peracid concentration for antimicrobial efficacy. For example, awater source is dosed amounts of the peracid and catalase use solutioncomposition until a peracid concentration within the water source isdetected within the preferred concentration range (e.g. about 1 ppm toabout 100 ppm peracid). In an aspect, it is preferred to have amicrobial count of less than about 100,000 microbes/mL, more preferablyless than about 10,000 microbes/mL, or more preferably less than about1,000 microbes/mL.

The methods of use as described herein can vary in the temperature andpH conditions associated with use of the aqueous treatment fluids. Forexample, the aqueous treatment fluids may be subjected to varyingambient temperatures according to the applications of use disclosedherein, including ranging from about 0° C. to about 130° C. in thecourse of the treatment operations. Preferably, the temperature range isbetween about 5° C. to about 100° C., more preferably between about 10°C. to about 80° C. However, as a majority of the antimicrobial activityof the compositions of the invention occurs over a short period of time,the exposure of the compositions to relatively high temperatures is nota substantial concern. In addition, the peracid composition aqueoustreatment fluids (i.e. use solutions) may be subjected to varying pHranges, such as from 1 to about 10.5. Preferably, the pH range is lessthan about 9, less than about 8.2 (pKa value of the representativeperacid peracetic acid) to ensure the effective antimicrobial efficacyof the peracid.

The antimicrobial compositions of the invention are fast-acting.However, the present methods require a certain minimal contact time ofthe compositions with the water in need of treatment for occurrence ofsufficient antimicrobial effect. The contact time can vary withconcentration of the use compositions, method of applying the usecompositions, temperature of the use compositions, pH of the usecompositions, amount of water to be treated, amount of soil orsubstrates in the water to be treated, or the like. The contact orexposure time can be at least about 15 seconds. In some embodiments, theexposure time is about 1 to 5 minutes. In other embodiments, theexposure time is at least about 10 minutes, 30 minutes, or 60 minutes.In other embodiments, the exposure time is a few minutes to hours. Thecontact time will further vary based upon the concentration of peracidin a use solution.

Beneficial Effects of the Methods of Use in Water Treatment

In an aspect, the methods of use provide an antimicrobial for use thatdoes not negatively impact the environment. Beneficially, thedegradation of the compositions of the invention provides a “green”alternative. In an aspect of the invention, utilizing peroxyacetic acidis beneficial as the by-products are non-toxic, non-persistent in theenvironment, certified as organic and permitted for discharge in surfacewaters.

In a further aspect, the methods of use provide an antimicrobial for usethat does not negatively interfere with friction reducers, viscosityenhancers and/or other functional ingredients. In a further aspect, themethods of use do not negatively interfere with any additionalfunctional agents utilized in the water treatment methods, including forexample, corrosion inhibitors, descaling agents and the like. Thecompositions administered according to the invention provide extremelyeffective control of microorganisms without adversely affecting thefunctional properties of any additive polymers of an aqueous system. Inaddition, the treated peracid composition use solutions provideadditional benefits to a system, including for example, reducingcorrosion within the system due to the decreased or substantiallyeliminated hydrogen peroxide from a treated peracid composition.Beneficially, the non-deleterious effects of the treated peracidcompositions (with or without a catalase) on the various functionalingredients used in water treatment methods are achieved regardless ofthe make-up of the water source in need of treatment.

In an additional aspect, the methods of use prevent the contamination ofsystems, such as well or reservoir souring. In further aspects, themethods of use prevent microbiologically-influenced corrosion of thesystems upon which it is employed.

In additional aspects of the invention, the reduction and/or eliminationof H₂O₂ from the systems reduces volume expansion within sealed systems(e.g. wells). As a result there is a significantly decreased oreliminated risk of well blow outs due to the removal of gases within theantimicrobial compositions used for treating the various water sources.

In further aspects, the methods of use employ the antimicrobial and/orbleaching activity of the peracid compositions. For example, theinvention includes a method for reducing a microbial population and/or amethod for bleaching. These methods can operate on an article, surface,in a body or stream of water or a gas, or the like, by contacting thearticle, surface, body, or stream with the compositions. Contacting caninclude any of numerous methods for applying the compositions,including, but not limited to, providing the antimicrobial peracidcompositions in an aqueous use solution and immersing any articles,and/or providing to a water source in need of treatment.

The compositions are suitable for antimicrobial efficacy against a broadspectrum of microorganisms, providing broad spectrum bactericidal andfungistatic activity. For example, the peracid biocides of thisinvention provide broad spectrum activity against wide range ofdifferent types of microorganisms (including both aerobic and anaerobicmicroorganisms), including bacteria, yeasts, molds, fungi, algae, andother problematic microorganisms associated with oil- and gas-fieldoperations.

Exemplary microorganisms susceptible to the peracid compositions of theinvention include, gram positive bacteria (e.g., Staphylococcus aureus,Bacillus species (sp.) like Bacillus subtilis, Clostridia sp.), gramnegative bacteria (e.g., Escherichia coli, Pseudomonas sp., Klebsiellapneumoniae, Legionella pneumophila, Enterobacter sp., Serratia sp.,Desulfovibrio sp., and Desulfotomaculum sp.), yeasts (e.g.,Saccharomyces cerevisiae and Candida albicans), molds (e.g., Aspergillusniger, Cephalosporium acremonium, Penicillium notatum, and Aureobasidiumpullulans), filamentous fungi (e.g., Aspergillus niger and Cladosporiumresinae), algae (e.g., Chlorella vulgaris, Euglena gracilis, andSelenastrum capricornutum), and other analogous microorganisms andunicellular organisms (e.g., phytoplankton and protozoa). Otherexemplary microorganisms susceptible to the peracid compositions of theinvention include the exemplary microorganisms disclosed in U.S. patentapplication US 2010/0160449 A1, e.g., the sulfur- or sulfate-reducingbacteria, such as Desulfovibrio and Desulfotomaculum species.

Use in Other Treatments

Additional embodiments of the invention include water treatments forvarious industrial processes for treating liquid systems. As usedherein, “liquid system” refers to flood waters or an environment withinat least one artificial artifact, containing a substantial amount ofliquid that is capable of undergoing biological fouling. Liquid systemsinclude but are not limited to industrial liquid systems, industrialwater systems, liquid process streams, industrial liquid processstreams, industrial process water systems, process water applications,process waters, utility waters, water used in manufacturing, water usedin industrial services, aqueous liquid streams, liquid streamscontaining two or more liquid phases, and any combination thereof.

In a further aspect, the compositions can also be used to treat otherliquid systems where both the compositions' antimicrobial function andoxidant properties can be utilized. Aside from the microbial issuessurrounding waste water, waste water is often rich in malodorouscompounds of reduced sulfur, nitrogen or phosphorous. A strong oxidantsuch as the compositions disclosed herein converts these compoundsefficiently to their odor free derivatives e.g. the sulfates, phosphatesand amine oxides. These same properties are very useful in the pulp andpaper industry where the property of bleaching is also of great utility.

C. SLICK WATER COMPOSITIONS AND USES THEREOF

The present invention also relates to slick water compositions useful inoil and/or gas drilling that comprise stable percarboxylic acidcompositions and uses thereof. In one aspect, the present invention isdirected to a composition, which composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;        -   or a compound having the following Formula (IB):

-   -   wherein    -   R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are        independently hydrogen or (C₁-C₆)alkyl;    -   R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are        independently hydrogen or (C₁-C₆)alkyl;    -   each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or        (C₂-C₆)alkynyl; and    -   n is a number from zero to 3;    -   or a salt thereof;    -   5) a second stabilizing agent, which is a compound having the        following Formula

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof;

-   -   6) a friction reducer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 20 ppm, and the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

In some embodiments, the present composition is an equilibratedcomposition that comprises peracid, hydrogen peroxide, carboxylic acidand a solvent, e.g., water. In some embodiments, the present compositiondoes not comprise a mineral acid, e.g., the mineral acids disclosed inWO 91/07375.

The present composition can comprise any suitable level of the hydrogenperoxide. In some embodiments, the hydrogen peroxide in the presentcompositions has a concentration of about 1 ppm to about 10 ppm, e.g., 1ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9 ppm, or 10 ppm.

The present composition can comprise any suitable level of the C₁-C₂₂percarboxylic acid relative to the level of the hydrogen peroxide. Insome embodiments, the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 6 times of the concentration of the hydrogen peroxide. Inother embodiments, the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 10 times of the concentration of the hydrogen peroxide.In still other embodiments, the C₁-C₂₂ percarboxylic acid has aconcentration of at least about 2, 3, 4, 5, 6, 7, 8, 9 or 10 times ofthe concentration of the hydrogen peroxide.

The present composition can comprise any suitable friction reducer. Insome embodiments, the friction reducer is a polyacrylamide polymerand/or copolymer, or an acrylamide-derived polymer and/or copolymer.Other exemplary friction reducers include the ones described in theabove Section B. The present composition can comprise any suitable levelof the friction reducer. In some embodiments, the friction reducer has aconcentration from about 50 ppm to about 5,000 ppm, preferably fromabout 100 ppm to about 1,000 ppm. In other embodiments, the frictionreducer has a concentration at about 50 ppm, 100 ppm, 200 ppm, 300 ppm,400 ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, 1,000 ppm, 2,000ppm, 3,000 ppm, 4,000 ppm, or 5,000 ppm.

The present composition can further comprise any substances suitable foroil and/or gas drilling. In some embodiments, the present compositioncan further comprise a proppant, a surfactant and/or a scale inhibitor.Any suitable proppant can be used. In some embodiments, the proppant isa sand or a ceramic bead. Any suitable scale inhibitor can be used. Insome embodiments, the scale inhibitor is a polymer, a phosphonate or aphosphate ester.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentcompositions. In some embodiments, the C₁-C₂₂ percarboxylic acid is aC₂-C₂₀ percarboxylic acid. In other embodiments, the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid. Other exemplary C₁-C₂₂ percarboxylicacids are described in the above Section B. The present composition cancomprise any suitable level of the C₁-C₂₂ percarboxylic acid andhydrogen peroxide. In some embodiments, the C₁-C₂₂ percarboxylic acidhas a concentration from about 10 ppm to about 30 ppm, e.g., 10 ppm, 15ppm, 20 ppm, 25 ppm, or 30 ppm, and the hydrogen peroxide has aconcentration from about 1 ppm to about 3 ppm, e.g., 1 ppm, 1.5 ppm, 2ppm, 2.5 ppm, or 3 ppm.

Any suitable first stabilizing agent can be used in the presentcompositions. In some embodiments, the first stabilizing agent is apicolinic acid, or a salt thereof. In other embodiments, the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.The first stabilizing agent can be used at any suitable concentration.In some embodiments, the first stabilizing agent has a concentrationfrom about 0.005 wt-% to about 5 wt-%. In other embodiments, the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%. In still other embodiments, the first stabilizing agent has aconcentration at about 0.005 wt-%, 0.01 wt-%, 0.1 wt-%, 1 wt-%, 2 wt-%,3 wt-%, 4 wt-%, or 5 wt-%. In yet other embodiments, the firststabilizing agent has a concentration at about 0.05 wt-%, 0.06 wt-%,0.07 wt-%, 0.08 wt-%, 0.09 wt-%, 0.10 wt-%, 0.11 wt-%, 0.12 wt-%, 0.13wt-%, 0.14 wt-%, or 0.15 wt-%.

Any suitable second stabilizing agent can be used in the presentcompositions. In some embodiments, the second stabilizing agent is1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), or a salt thereof.The second stabilizing agent can be used at any suitable concentration.In some embodiments, the second stabilizing agent has a concentrationfrom about 0.1 wt-% to about 10 wt-%, e.g., 0.1 wt-%, 0.5 wt-%, 1 wt-%,2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%, or 10wt-%. In other embodiments, the second stabilizing agent has aconcentration from about 0.5 wt-% to about 5 wt-%, e.g., 0.5 wt-%, 1wt-%, 1.5 wt-%, 2 wt-%, 2.5 wt-%, 3 wt-%, 3.5 wt-%, 4 wt-%, 4.5 wt-% or5 wt-%. In still other embodiments, the second stabilizing agent has aconcentration from about 0.6 wt-% to about 1.8 wt-%, e.g., 0.6 wt-%, 0.7wt-%, 0.8 wt-%, 0.9 wt-%, 1.0 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4wt-%, 1.5 wt-%, 1.6 wt-%, 1.7 wt-%, or 1.8 wt-%.

In some embodiments, the first stabilizing agent is a2,6-pyridinedicarboxylic acid, or a salt thereof, and the secondstabilizing agent is HEDP, or a salt thereof.

The present compositions can retain any suitable level or percentage ofthe C₁-C₂₂ percarboxylic acid activity for any suitable time after thecomposition is formed. In some embodiments, the present compositionretains at least about 60%, 65%, 70%, 75%, 80%, 85% or 90% of theinitial C₁-C₂₂ percarboxylic acid activity for any suitable time afterthe composition is formed. In other embodiments, the present compositionretains at least about 60% of the initial C₁-C₂₂ percarboxylic acidactivity for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,20, 25, 30 minutes, 1, 2, 5, 10, 15, 20 or 24 hours, or longer after thecomposition is formed.

In some embodiments, the present compositions can comprise a peroxidaseor a catalase to further reduce the hydrogen peroxide concentration. Anysuitable peroxidase or a catalase can be used in the presentcompositions. Exemplary peroxidases and catalases are described in theabove Section B. In other embodiments, the present compositions canfurther comprise a substance that aids solubilization of the firstand/or second stabilizing agent(s). Exemplary substances that can aidsolubilization of the first and/or second stabilizing agent(s) includehydrotropes such as sodium xylene sulfonate, sodium cumene sulfonates,and surfactants, such as anionic surfactants and noinionic surfactants.

In another aspect, the present invention is directed to a method forslick water fracturing, which method comprises directing the abovecomposition into a subterranean environment.

The present compositions can be directed into a subterranean environmentat any suitable speed. In some embodiments, the present composition isdirected into a subterranean environment at a speed faster than 30barrel (bbl)/min. In other embodiments, the present composition isdirected into a subterranean environment at a speed from about 50bbl/min. to about 100 bbl/min., e.g., 50, 60, 70, 80, 90 or 100 bbl/min.

The present compositions can be directed into any suitable subterraneanenvironment. In some embodiments, the subterranean environment comprisesa well in a shale gas and/or oil reservoir.

The present compositions can be directed into a subterranean environmentby any suitable methods. In some embodiments, the composition is pumpeddown a well-bore.

D. GEL BASED COMPOSITIONS AND USES THEREOF

The present invention further relates to gel based compositions usefulin oil and/or gas drilling that comprise stable percarboxylic acidcompositions and uses thereof. In one aspect, the present invention isdirected to a composition, which composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

or a compound having the following Formula (IB):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

-   -   5) a second stabilizing agent, which is a compound having the        following Formula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and R⁶ ishydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (BB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof;

-   -   6) a viscosity enhancer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 15 ppm, and said C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

In some embodiments, the present composition is an equilibratedcomposition that comprises peracid, hydrogen peroxide, carboxylic acidand a solvent, e.g., water. In some embodiments, the present compositiondoes not comprise a mineral acid, e.g., the mineral acids disclosed inWO 91/07375.

The present composition can comprise any suitable level of the hydrogenperoxide. In some embodiments, the hydrogen peroxide in the presentcompositions has a concentration of about 1 ppm to about 15 ppm, e.g., 1ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9 ppm, 10 ppm, 11ppm, 12 ppm, 13 ppm, 14 ppm, or 15 ppm.

The present composition can comprise any suitable level of the C₁-C₂₂percarboxylic acid relative to the level of the hydrogen peroxide. Insome embodiments, the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 6 times of the concentration of the hydrogen peroxide. Inother embodiments, the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 10 times of the concentration of the hydrogen peroxide.In still other embodiments, the C₁-C₂₂ percarboxylic acid has aconcentration of at least about 2, 3, 4, 5, 6, 7, 8, 9 or 10 times ofthe concentration of the hydrogen peroxide.

Any suitable viscosity enhancer can be used in the present compositions.In some embodiments, the viscosity enhancer is a conventional lineargel, a borate-crosslinked gel, an organometallic-crosslinked gel or analuminium phosphate-ester oil gel. Other exemplary viscosity enhancersinclude the ones described in the above Section B. The viscosityenhancer can be used at any suitable levels. In some embodiments, theviscosity enhancer has a concentration from about 2 to about 100 unitsof pounds per thousand gallons, preferably from about 5 to about 65units of pounds per thousand gallons. In other embodiments, theviscosity enhancer has a concentration at about 2, 3, 4, 5, 6, 7, 8, 9,10, 20, 30, 40, 50, 60, 70, 80, 90 or 100 units of pounds per thousandgallons.

The present composition can further comprise any substances suitable foroil and/or gas drilling. In some embodiments, the present compositioncan further comprise a proppant, a surfactant, a scale inhibitor and/ora breaker. Any suitable proppant can be used. In some embodiments, theproppant is a sand or a ceramic bead. Any suitable scale inhibitor canbe used. In some embodiments, the scale inhibitor is a polymer, aphosphonate or a phosphate ester. Any suitable breaker can be used. Insome embodiments, the breaker is an oxidizer, an enzyme or a pHmodifier.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentcompositions. In some embodiments, the C₁-C₂₂ percarboxylic acid is aC₂-C₂₀ percarboxylic acid. In other embodiments, the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid. Other exemplary C₁-C₂₂ percarboxylicacids are described in the above Section B.

The present composition can comprise any suitable level of the C₁-C₂₂percarboxylic acid and hydrogen peroxide. In some embodiments, theC₁-C₂₂ percarboxylic acid has a concentration that is effective for itsanti-microbial function and the hydrogen peroxide has a concentrationthat will not cause gel failure. In other embodiments, the hydrogenperoxide has a concentration that is about 14 ppm or less. In stillother embodiments, the C₁-C₂₂ percarboxylic acid has a concentrationfrom about 10 ppm to about 30 ppm, e.g., 10 ppm, 15 ppm, 20 ppm, 25 ppm,or 30 ppm, and the hydrogen peroxide has a concentration from about 1ppm to about 3 ppm, e.g., 1 ppm, 1.5 ppm, 2 ppm, 2.5 ppm, or 3 ppm.

Any suitable first stabilizing agent can be used in the presentcompositions. In some embodiments, the first stabilizing agent is apicolinic acid, or a salt thereof. In other embodiments, the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.The first stabilizing agent can be used at any suitable concentration.In some embodiments, the first stabilizing agent has a concentrationfrom about 0.005 wt-% to about 5 wt-%. In other embodiments, the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%. In still other embodiments, the first stabilizing agent has aconcentration at about 0.005 wt-%, 0.01 wt-%, 0.1 wt-%, 1 wt-%, 2 wt-%,3 wt-%, 4 wt-%, or 5 wt-%. In yet other embodiments, the firststabilizing agent has a concentration at about 0.05 wt-%, 0.06 wt-%,0.07 wt-%, 0.08 wt-%, 0.09 wt-%, 0.10 wt-%, 0.11 wt-%, 0.12 wt-%, 0.13wt-%, 0.14 wt-%, 0.15 wt-%.

Any suitable second stabilizing agent can be used in the presentcompositions. In some embodiments, the second stabilizing agent is1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), or a salt thereof.The second stabilizing agent can be used at any suitable concentration.In some embodiments, the second stabilizing agent has a concentrationfrom about 0.1 wt-% to about 10 wt-%, e.g., 0.1 wt-%, 0.5 wt-%, 1 wt-%,2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%, or 10wt-%. In other embodiments, the second stabilizing agent has aconcentration from about 0.5 wt-% to about 5 wt-%, e.g., 0.5 wt-%, 1wt-%, 1.5 wt-%, 2 wt-%, 2.5 wt-%, 3 wt-%, 3.5 wt-%, 4 wt-%, 4.5 wt-% or5 wt-%. In still other embodiments, the second stabilizing agent has aconcentration from about 0.6 wt-% to about 1.8 wt-%, e.g., 0.6 wt-%, 0.7wt-%, 0.8 wt-%, 0.9 wt-%, 1.0 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4wt-%, 1.5 wt-%, 1.6 wt-%, 1.7 wt-%, or 1.8 wt-%.

In some embodiments, the first stabilizing agent is a2,6-pyridinedicarboxylic acid, or a salt thereof, and the secondstabilizing agent is HEDP, or a salt thereof.

The present compositions can retain any suitable level or percentage ofthe C₁-C₂₂ percarboxylic acid activity for any suitable time after thecomposition is formed. In some embodiments, the present compositionretains at least about 60%, 65%, 70%, 75%, 80%, 85% or 90% of theinitial C₁-C₂₂ percarboxylic acid activity for any suitable time afterthe composition is formed. In other embodiments, the present compositionretains at least about 60% of the initial C₁-C₂₂ percarboxylic acidactivity for at least 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15,20, 25, 30 minutes, 1, 2, 5, 10, 15, 20 or 24 hours, or longer after thecomposition is formed.

In some embodiments, the present compositions can comprise a peroxidaseor a catalase to further reduce the hydrogen peroxide concentration. Anysuitable peroxidase or a catalase can be used in the presentcompositions. Exemplary peroxidases and catalases are described in theabove Section B. In other embodiments, the present compositions canfurther comprise a substance that aids solubilization of the firstand/or second stabilizing agent(s). Exemplary substances that can aidsolubilization of the first and/or second stabilizing agent(s) includehydrotropes such as sodium xylene sulfonate, sodium cumene sulfonates,and surfactants, such as anionic surfactants and noinionic surfactants.

In another aspect, the present invention is directed to a method forhigh-viscosity fracturing, which method comprises directing the abovecomposition into a subterranean environment.

The present methods can be used to direct the above composition into anysuitable subterranean environment. In some embodiments, the presentmethods can be used to direct the above composition into a subterraneanenvironment comprising a well in a gas and/or oil field.

Those skilled in the art will recognize, or be able to ascertain usingno more than routine experimentation, numerous equivalents to thespecific procedures, embodiments, claims, and examples described herein.Such equivalents are considered to be within the scope of this inventionand covered by the claims appended hereto. The contents of allreferences, patents, and patent applications cited throughout thisapplication are hereby incorporated by reference to the same extent asif each individual publication or patent application was specificallyand individually indicated as incorporated by reference. Allpublications and patent applications in this specification areindicative of the level of ordinary skill in the art to which thisinvention pertains. The invention is further illustrated by thefollowing examples, which should not be construed as further limiting.

E. METHODS FOR TREATING A TARGET

In yet another aspect, the present invention is directed to a method fortreating a target, which method comprises a step of contacting a targetwith a composition in a diluted level to form a treated targetcomposition, wherein said composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

-   -   or a salt thereof;    -   or a compound having the following Formula (IB):

wherein

R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

-   -   5) a second stabilizing agent, which is a compound having the        following Formula

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof; and

wherein said hydrogen peroxide has a concentration of at least about 0.1wt-%, the C₁-C₂₂ percarboxylic acid has a concentration of at leastabout 2 times of the concentration of said hydrogen peroxide, and saidcomposition has a pH at about 4 or less, and

wherein said treated target composition comprises from about 1 ppm toabout 10,000 ppm of said C₁-C₂₂ percarboxylic acid, and said contactingstep lasts for sufficient time to stabilize or reduce microbialpopulation in and/or on said target or said treated target composition.

In some embodiments, the composition used in the present methods is anequilibrated composition that comprises peracid, hydrogen peroxide,carboxylic acid and a solvent, e.g., water. In some embodiments, thecomposition used in the present methods does not comprise a mineralacid, e.g., the mineral acids disclosed in WO 91/07375.

The composition used in the present methods can comprise any suitablelevel of the hydrogen peroxide. In some embodiments, the hydrogenperoxide in the equilibrated composition has a concentration of about0.1% to about 15%, e.g., about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%,0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%,or 15%. Prior to or during use, the exemplary compositions can bediluted to a desired level.

The composition used in the present methods can comprise any suitablelevel of the C₁-C₂₂ percarboxylic acid relative to the level of thehydrogen peroxide. In some embodiments, the C₁-C₂₂ percarboxylic acidhas a concentration of at least about 6 times of the concentration ofthe hydrogen peroxide. In other embodiments, the C₁-C₂₂ percarboxylicacid has a concentration of at least about 10 times of the concentrationof the hydrogen peroxide. In still other embodiments, the C₁-C₂₂percarboxylic acid has a concentration of at least about 2, 3, 4, 5, 6,7, 8, 9 or 10 times of the concentration of the hydrogen peroxide.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentmethods. In some embodiments, the C₁-C₂₂ percarboxylic acid is a C₂-C₂₀percarboxylic acid. In other embodiments, the C₁-C₂₂ percarboxylic acidcomprises peroxyacetic acid, peroxyoctanoic acid and/or peroxysulfonatedoleic acid. Other exemplary C₁-C₂₂ percarboxylic acids are described inthe above Section B. The composition used in the present methods cancomprise any suitable level of the C₁-C₂₂ percarboxylic acid andhydrogen peroxide. In some embodiments, the C₁-C₂₂ percarboxylic acid inthe equilibrated composition has a concentration from about 0.1% toabout 30%, e.g., about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%,0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%,16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or30%. Prior to or during use, the exemplary compositions can be dilutedto a desired level.

Any suitable first stabilizing agent can be used in the composition usedin the present methods. In some embodiments, the first stabilizing agentis a picolinic acid, or a salt thereof. In other embodiments, the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.The first stabilizing agent can be used at any suitable concentration.In some embodiments, the first stabilizing agent has a concentrationfrom about 0.005 wt-% to about 5 wt-%. In other embodiments, the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%. In still other embodiments, the first stabilizing agent has aconcentration at about 0.005 wt-%, 0.01 wt-%, 0.1 wt-%, 1 wt-%, 2 wt-%,3 wt-%, 4 wt-%, or 5 wt-%. In yet other embodiments, the firststabilizing agent has a concentration at about 0.05 wt-%, 0.06 wt-%,0.07 wt-%, 0.08 wt-%, 0.09 wt-%, 0.10 wt-%, 0.11 wt-%, 0.12 wt-%, 0.13wt-%, 0.14 wt-%, or 0.15 wt-%.

Any suitable second stabilizing agent can be used in the presentcompositions. In some embodiments, the second stabilizing agent is1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), or a salt thereof.The second stabilizing agent can be used at any suitable concentration.In some embodiments, the second stabilizing agent has a concentrationfrom about 0.1 wt-% to about 10 wt-%, e.g., 0.1 wt-%, 0.5 wt-%, 1 wt-%,2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%, or 10wt-%. In other embodiments, the second stabilizing agent has aconcentration from about 0.5 wt-% to about 5 wt-%, e.g., 0.5 wt-%, 1wt-%, 1.5 wt-%, 2 wt-%, 2.5 wt-%, 3 wt-%, 3.5 wt-%, 4 wt-%, 4.5 wt-% or5 wt-%. In still other embodiments, the second stabilizing agent has aconcentration from about 0.6 wt-% to about 1.8 wt-%, e.g., 0.6 wt-%, 0.7wt-%, 0.8 wt-%, 0.9 wt-%, 1.0 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4wt-%, 1.5 wt-%, 1.6 wt-%, 1.7 wt-%, or 1.8 wt-%.

In some embodiments, the first stabilizing agent is a2,6-pyridinedicarboxylic acid, or a salt thereof, and the secondstabilizing agent is HEDP, or a salt thereof.

The composition used in the present methods can retain any suitablelevel or percentage of the C₁-C₂₂ percarboxylic acid activity for anysuitable time after the treated target composition is formed. In someembodiments, the present composition retains at least about 50%, 55%,60%, 65%, 70%, 75%, 80%, 85% or 90% of the initial C₁-C₂₂ percarboxylicacid activity for any suitable time after the treated target compositionis formed. In other embodiments, the present composition retains atleast about 60% of the initial C₁-C₂₂ percarboxylic acid activity for atleast 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30minutes, 1, 2, 5, 10, 15, 20 or 24 hours, or longer after the treatedtarget composition is formed.

In some embodiments, the composition used in the present methods cancomprise a peroxidase or a catalase to further reduce the hydrogenperoxide concentration. Any suitable peroxidase or a catalase can beused in the present compositions. Exemplary peroxidases and catalasesare described in the above Section B. In other embodiments, thecomposition used in the present methods can further comprise a substancethat aids solubilization of the first and/or second stabilizingagent(s). Exemplary substances that can aid solubilization of the firstand/or second stabilizing agent(s) include hydrotropes such as sodiumxylene sulfonate, sodium cumene sulfonates, and surfactants, such asanionic surfactants and noinionic surfactants.

The present methods can be used for treating any suitable target. Forexample, the target can be a food item or a plant item and/or at least aportion of a medium, a container, an equipment, a system or a facilityfor growing, holding, processing, packaging, storing, transporting,preparing, cooking or serving the food item or the plant item.

The present methods can be used for treating any suitable plant item. Insome embodiments, the plant item is a grain, fruit, vegetable or flowerplant item. In other embodiments, the plant item is a living plant itemor a harvested plant item. In still other embodiments, the plant itemcomprises a seed, a tuber, a growing plant, a cutting, or a root stock.In yet other embodiments, the present methods are used for treating aliving plant tissue comprising treating the plant tissue with the abovecomposition in a diluted level to stabilize or reduce microbialpopulation in and/or on the plant tissue. In yet other embodiments, thepresent methods are used for growing a plant on a hydroponic substratein a hydroponic liquid supply medium, comprising: (a) establishing agrowing and living plant tissue in the hydroponic substrate; (b)contacting the living plant tissue, the hydroponic substrate and thehydroponic liquid with a diluted composition of the present invention tostabilize or reduce microbial population in and/or on the living planttissue; and (c) harvesting a usable plant product with reduced microbialcontamination.

The present methods can be used for treating any suitable food item. Forexample, the food item can be an animal product, e.g., an animal carcassor an egg, a fruit item, a vegetable item, or a grain item. In someembodiments, the animal carcass can be a beef, pork, veal, buffalo,lamb, fish, sea food or poultry carcass. In other embodiments, the seafood carcass can be scallop, shrimp, crab, octopus, mussel, squid orlobster. In still other embodiments, the fruit item can be a botanicfruit, a culinary fruit, a simple fruit, an aggregate fruit, a multiplefruit, a berry, an accessory fruit or a seedless fruit. In yet otherembodiments, the vegetable item can be a flower bud, a seed, a leaf, aleaf sheath, a bud, a stem, a stem of leaves, a stem shoot, a tuber, awhole-plant sprout, a root or a bulb. In yet other embodiments, thegrain item can be maize, rice, wheat, barley, sorghum, millet, oat,triticale, rye, buckwheat, fonio or quinoa.

The present methods can be used for treating a target that is at least aportion of a container, an equipment, a system or a facility forholding, processing, packaging, storing, transporting, preparing,cooking or serving the food item or the plant item. In some embodiments,the target is at least a portion of a container, an equipment, a systemor a facility for holding, processing, packaging, storing, transporting,preparing, cooking or serving a meat item, a fruit item, a vegetableitem, or a grain item. In other embodiments, the target is at least aportion of a container, an equipment, a system or a facility forholding, processing, packaging, storing, or transporting an animalcarcass. In still other embodiments, the target is at least a portion ofa container, an equipment, a system or a facility used in foodprocessing, food service or health care industry. In yet otherembodiments, the target is at least a portion of a fixed in-placeprocess facility. An exemplary fixed in-place process facility cancomprise a milk line dairy, a continuous brewing system, a pumpable foodsystem or a beverage processing line.

The present methods can be used for treating a target that is at least aportion of a solid surface or liquid media. In some embodiments, thesolid surface is an inanimate solid surface. The inanimate solid surfacecan be contaminated by a biological fluid, e.g., a biological fluidcomprising blood, other hazardous body fluid, or a mixture thereof. Inother embodiments, the solid surface can be a contaminated surface. Anexemplary contaminated surface can comprise the surface of food servicewares or equipment, or the surface of a fabric.

The treated target composition can comprise any suitable level of theC₁-C₂₂ percarboxylic acid. In some embodiments, the treated targetcomposition comprises from about 10 ppm to about 200 ppm of the C₁-C₂₂percarboxylic acid, e.g., about 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm,60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm, 190 ppm, or 200 ppm of theC₁-C₂₂ percarboxylic acid.

The treated target composition can comprise any suitable C₁-C₂₂percarboxylic acid. In some embodiments, the treated target compositioncomprises peroxyacetic acid, peroxyoctanoic acid and/or peroxysulfonatedoleic acid.

The treated target composition can comprise any suitable level of thehydrogen peroxide. In some embodiments, the treated target compositioncomprises from about 1 ppm to about 15 ppm of the hydrogen peroxide,e.g., about 1 ppm, 2 ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9ppm, 10 ppm, 11 ppm, 12 ppm, 13 ppm, 14 ppm, or 15 ppm of the hydrogenperoxide.

The treated target composition can comprise any suitable level of theC₁-C₂₂ percarboxylic acid relative to the level of the hydrogenperoxide. In some embodiments, the treated target composition comprisesthe C₁-C₂₂ percarboxylic acid that has a concentration of at least about2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20times of the concentration of the hydrogen peroxide.

The treated target composition can comprise any suitable firststabilizing agent and second stabilizing agent. In some embodiments, thetreated target composition comprises a first stabilizing agent that is a2,6-pyridinedicarboxylic acid, or a salt thereof, and a secondstabilizing agent that is HEDP, or a salt thereof.

The treated target composition can retain any suitable level of theinitial C₁-C₂₂ percarboxylic acid activity for any suitable time. Insome embodiments, the treated target composition retains at least about50%, 60%, 70%, 80%, 90%, 95%, 99%, or 100% of the initial C₁-C₂₂percarboxylic acid activity for any suitable time. In other embodiments,the treated target composition retains a suitable level of the initialC₁-C₂₂ percarboxylic acid activity for at least 1 minute, 2 minutes, 3minutes, 4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9minutes, 10 minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or15 minutes after the treated target composition is formed. In stillother embodiments, the treated target composition retains at least about60% of the initial C₁-C₂₂ percarboxylic acid activity for 15 minutesafter the treated target composition is formed.

The contacting step can last for any suitable time. In some embodiments,the contacting step lasts for at least 10 seconds, 20 seconds, 30seconds, 40 seconds, 50 seconds, 1 minute, 10 minutes, 30 minutes, 1hour, 2 hours, 4 hours, 8 hours, 16 hours, 1 day, 3 days, 1 week, orlonger.

The diluted composition can be applied to the target in any suitablemanner. In some embodiments, the diluted composition is applied to thetarget by means of a spray, a fog, or a foam. In other embodiments, thediluted composition is applied to the target by applying in the form ofa thickened or gelled solution. In still other embodiments, all or partof the target is dipped in the diluted composition. The target and/orthe diluted composition can be subject to any suitable movement to helpor facilitate the contact between the target and the dilutedcomposition. In some embodiments, the diluted composition can beagitated. In other embodiments, the diluted composition can be sprayedonto a target, e.g., an animal carcass, under suitable pressure and at asuitable temperature. For example, the diluted composition can besprayed onto an animal carcass at a pressure of at least 50 psi at atemperature of up to about 60° C., resulting in a contact time of atleast 30 seconds.

The present methods can comprise any suitable, additional steps. In someembodiments, the present methods can comprise a vacuum treatment step.In other embodiments, the present methods can comprise a step ofapplying an activated light source to the target, e.g., an animalcarcass.

The present methods can be used to achieve any suitable reduction of themicrobial population in and/or on the target or the treated targetcomposition. In some embodiments, the present methods can be used toreduce the microbial population in and/or on the target or the treatedtarget composition by at least one log₁₀. In other embodiments, thepresent methods can be used to reduce the microbial population in and/oron the target or the treated target composition by at least two log₁₀.In still other embodiments, the present methods can be used to reducethe microbial population in and/or on the target or the treated targetcomposition by at least three log₁₀.

The present methods can be used to stabilize or reduce any suitablemicrobial population in and/or on the target or the treated targetcomposition. In some embodiments, the present methods can be used tostabilize or reduce a prokaryotic microbial population in and/or on thetarget or the treated target composition. Exemplary prokaryoticmicrobial population can comprise a bacterial or an archaeal population.In other embodiments, the present methods can be used to stabilize orreduce an eukaryotic microbial population in and/or on the target or thetreated target composition. Exemplary eukaryotic microbial populationcan comprise a protozoal or fungal population. In still otherembodiments, the present methods can be used to stabilize or reduce aviral population in and/or on the target or the treated targetcomposition. Exemplary viral population can comprise a population of aDNA virus, a RNA virus, and a reverse transcribing virus.

The present methods can be used to stabilize or reduce a microbialpopulation in and/or on the target or the treated target composition,wherein the target is a food item or a plant item and the contactingstep minimizes or does not induce an organoleptic effect in and/or onthe food item or a plant item. Typical organoleptic properties includethe aspects of food or other substances as experienced by the senses,including taste, sight, smell, and touch, in cases where dryness,moisture, and stale-fresh factors are to be considered. See e.g., JasperWomach, the Congressional Research Service document “Report forCongress: Agriculture: A Glossary of Term, Programs, and Laws, 2005Edition.” In some embodiments, organoleptic procedures are performed aspart of the meat and poultry inspections to detect signs of disease orcontamination. In other embodiments, organoleptic tests are conducted todetermine if package materials and components can transfer tastes andodors to the food or pharmaceutical products that they are packaged in.Shelf life studies often use taste, sight, and smell (in addition tofood chemistry and toxicology tests) to determine whether a food productis suitable for consumption. In still other embodiments, organoleptictests are conducted as part of the Hurdle technology. Typically, Hurdletechnology refers to an intelligent combination of hurdles which securesthe microbial safety and stability as well as the organoleptic andnutritional quality and the economic viability of food products. Seegenerally, Leistner L (1995) “In Gould G W (Ed.) New Methods of FoodPreservation, Springer, pp. 1-21; and Leistner I (2000)” InternationalJournal of Food Microbiology, 55:181-186.

The present methods can be conducted at any suitable temperature. Insome embodiments, the present methods are conducted at a temperatureranging from about 0° C. to about 70° C., e.g., from about 0° C. toabout 4° C. or 5° C., from about 5° C. to about 10° C., from about 11°C. to about 20° C., from about 21° C. to about 30° C., from about 31° C.to about 40° C., including at about 37° C., from about 41° C. to about50° C., from about 51° C. to about 60° C., or from about 61° C. to about70° C.

The present methods can be used in the methods, processes or proceduresdescribed and/or claimed in U.S. Pat. Nos. 5,200,189, 5,314,687 and5,718,910. In some embodiments, the present methods can be used ofsanitizing facilities or equipment comprises the steps of contacting thefacilities or equipment with the diluted (or use) composition of thepresent invention at a temperature in the range of about 4° C. to about60° C. The diluted (or use) composition is then circulated or left incontact with the facilities or equipment for a time sufficient tosanitize (generally at least 30 seconds) and the treated targetcomposition is thereafter drained or removed from the facilities orequipment.

As noted above, the present methods are useful in the cleaning orsanitizing of processing facilities or equipment in the food service,food processing or health care industries. Examples of processfacilities in which the present methods can be employed include a milkline dairy, a continuous brewing system, food processing lines such aspumpable food systems and beverage lines, etc. Food service wares canalso be disinfected with the present methods. The present methods arealso useful in sanitizing or disinfecting solid surfaces such as floors,counters, furniture, medical tools and equipment, etc., found in thehealth care industry. Such surfaces often become contaminated withliquid body spills such as blood, other hazardous body fluids ormixtures thereof.

Generally, the actual cleaning of the in-place system or other surface(i.e., removal of unwanted offal therein) can be accomplished with adifferent material such as a formulated detergent which is introducedwith heated water. After this cleaning step, the present composition canbe applied or introduced into the system at a use solution concentrationin unheated, ambient temperature water. In some embodiments, the presentcomposition is found to remain in solution in cold (e.g., 40° F./4° C.)water and heated (e.g., 140° F./60° C.) water. Although it is notnormally necessary to heat the aqueous use solution of the presentcomposition, under some circumstances heating may be desirable tofurther enhance its antimicrobial activity.

In some embodiments, a method of sanitizing substantially fixed in-placeprocess facilities comprises the following steps. The diluted (or use)composition of the present invention is introduced into the processfacilities at a temperature in the range of about 4° C. to about 60° C.After introduction of the use solution, the solution is circulatedthroughout the system for a time sufficient to sanitize the processfacilities (i.e., to kill undesirable microorganisms). After the systemhas been sanitized by means of the present composition, the usecomposition or solution is drained from the system. Upon completion ofthe sanitizing step, the system optionally may be rinsed with othermaterials such as potable water. The present composition is preferablycirculated through the process facilities for 10 minutes or less.

In other embodiments, the present composition may also be employed bydipping food processing equipment into the diluted (or use) compositionor solution of the present invention, soaking the equipment for a timesufficient to sanitize the equipment, and wiping or draining excesssolution off the equipment. The composition may be further employed byspraying or wiping food processing surfaces with the use solution,keeping the surfaces wet for a time sufficient to sanitize the surfaces,and removing the excess composition or solution by wiping, drainingvertically, vacuuming, etc.

In still other embodiments, the present composition may also be used ina method of sanitizing hard surfaces such as institutional typeequipment, utensils, dishes, health care equipment or tools, and otherhard surfaces. The present composition may also be employed insanitizing clothing items or fabric which has become contaminated. Theuse composition is contacted with any of the above contaminated surfacesor items at use temperatures in the range of about 4° C. to about 60° C.for a period of time effective to sanitize, disinfect, or sterilize thesurface or item. For example, the concentrate composition can beinjected into the wash or rinse water of a laundry machine and contactedwith contaminated fabric for a time sufficient to sanitize the fabric.Excess composition or solution can then be removed by rinsing orcentrifuging the fabric.

The present methods can be used in the methods, processes or proceduresdescribed and/or claimed in U.S. Pat. Nos. 6,165,483 and 6,238,685B1, totreat field or greenhouse grown plant tissue, seeds, fruits, and growingmedia and containers. The present composition in diluted (or use) formcan lower the natural, plant pathogen and human pathogenic microbialload resulting in less waste to molding, spoilage, and destructionbecause of pathogenic poisons.

In some embodiments, the present composition comprising mixed peracidscan be used to protect growing plant tissue from the undesirable effectsof microbial attack. The mixed peracid materials can be applied togrowing plant tissues and can provide residual antimicrobial effectsafter the plant has completed its growth cycle, fruit or vegetablematerial have been harvested and sent to market. The present compositioncomprising mixed peracids can be an effective treatment of living orgrowing plant tissues including seeds, roots, tubers, seedlings,cuttings, rooting stock, growing plants, produce, fruits and vegetables,etc. Under certain circumstances, a single peroxyacid material can beeffective, however, in other circumstances, a mixed peroxy acid hassubstantially improved and surprising properties.

In some embodiments, the invention involves a peroxyacid antimicrobialconcentrate and diluted end use composition including an effectivemicrobicidal amount of a C₂-C₄ peroxycarboxylic acid such as peraceticacid, an effective microbicidal amount of a C₅-C₁₂peroxyacid, preferablywith a C₆-C₁₂ or a C₈-C₁₂ peroxy acid, or mixtures thereof, and thefirst and second stabilizing agents described above. The concentratecomposition can be diluted with a major proportion of water to form anantimicrobial sanitizing use solution having a pH in the range of about2 to 8, with a C₂-C₄ peroxycarboxylic acid concentration of at leastabout 4 ppm, preferably about 10 to 75 ppm, and a C₅-C₁₂, a C₆-C₁₂, or aC₈-C₁₂ peroxyacid concentration of at least about 1 ppm, preferablyabout 1 to 25 ppm. Other components may be added such as a hydrotropecoupling agent for solubilizing the peroxyfatty acid in the concentrateform and when the concentrate composition is diluted with water.

In other embodiments, the invention involves a method of controllingfungi and microbial plant pathogens in growing plants by treating saidgrowing plants with a dilute aqueous solution comprising an effectiveamount of a C₂-C₄ peroxycarboxylic acid, an aliphatic C₅-C₁₂, a C₆-C₁₂or a C₈-C₁₂ peroxycarboxylic acid, and the first and second stabilizingagents described above.

In still other embodiments, the invention further involves a process forcontrolling fungi and microbial plant pathogens in growing plants bydiluting in an aqueous liquid a concentrate containing: about 1 to 20wt-% of a C₂-C₄ peroxycarboxylic acid; about 0.1 to 20 wt-% of analiphatic C₅-C₁₂, a C₆-C₁₂ or a C₈-C₁₂ peroxycarboxylic acid, and thefirst and second stabilizing agents described above, to form a solution;and contacting said growing plants with said solution.

In yet other embodiments, the invention further involves a process forcontrolling fungi and microbial plant pathogens in growing plants bydiluting in an aqueous liquid a concentrate containing: about 1 to 20wt-% of a C₂-C₄ peroxycarboxylic acid; about 0.1 to 20 wt-% of analiphatic C₅-C₁₂, a C₆-C₁₂ or a C₈-C₁₂ peroxycarboxylic acid; about 5 to40 wt-% of a C₂-C₄ carboxylic acid; about 1 to 20 wt-% of an aliphaticC₈-C₁₂ carboxylic acid; about 1 to 30 wt-% of hydrogen peroxide, and thefirst and second stabilizing agents described above, to form a solution;and contacting said growing plants with said solution.

As disclosed in U.S. Pat. Nos. 6,165,483 and 6,238,685B1, a low pH,(e.g., preferably less than 7) C₅+ peroxyacids such as peroxyfatty acidsare very potent biocides at low levels when used in combination with aC₂-C₄ peroxycarboxylic acid such as peroxyacetic acid, a synergisticeffect is obtained, providing a much more potent biocide than can beobtained by using these components separately. This means thatsubstantially lower concentrations of biocide can be used to obtainequal biocidal effects.

As the term is used herein, a C₅-C₁₂ peroxyacid (or peracid) is intendedto mean the product of the oxidation of a C₅-C₁₂ acid such as a fattyacid, or a mixture of acids, to form a peroxyacid having from about 5 to12 carbon atoms per molecule. The C₅-C₁₂ peroxyacids are preferablyaliphatic (straight or branched). A C₂-C₄ peroxycarboxylic acid isintended to mean the product of oxidation of a C₂-C₄ carboxylic acid, ora mixture thereof. This includes both straight and branched a C₂-C₄carboxylic acids.

In yet other embodiments, the invention is directed a method ofcontrolling fungi and microbial plant pathogens in growing plants. Thistreatment utilizes a combination of two different peroxy acids. Thismixture comprises at least 4 parts per million (ppm) of a smaller C₂-C₄peroxy carboxylic acid and at least 1 ppm of a larger C₅-C₁₂ peroxycarboxylic acid, and the first and second stabilizing agents describedabove. The preferred mixture comprises at least 4 ppm of a smaller C₂-C₄peroxy acid and at least 1 ppm of a large aliphatic C₈-C₁₂ peroxy acid,and the first and second stabilizing agents described above.

An especially preferred embodiment of the composition includes a mixtureof peroxyacetic acid and peroctanoic acid.

In some embodiments, the composition used in the present methods alsomay contain a hydrotrope for the purpose of increasing the aqueoussolubility of various slightly soluble organic compounds. The preferredembodiment of the composition utilizes a hydrotrope chosen from thegroup of n-octanesulfonate, a xylene sulfonate, a naphthalene sulfonate,ethylhexyl sulfate, lauryl sulfate, an amine oxide, or a mixturethereof.

In some embodiments, the composition used in the present methods mayalso contain a chelating agent for the purpose of removing ions fromsolution. The preferred embodiment of the invention uses1-hydroxyethylidene-1,1-diphosphonic acid.

In some embodiments, the invention also provides a process ofcontrolling fungi and microbial plant pathogens in growing plants. Inthis embodiment, the plant is contacted with a solution made by dilutingin an aqueous liquid a concentrate comprising two peroxy acids, and thefirst and second stabilizing agents described above. This mixtureincludes C₂-C₄ peroxy carboxylic acid and a larger C₈-C₁₂ peroxycarboxylic acid. The preferred mixture includes about 1-20 weightpercent (wt %) of a smaller C₂-C₄ peroxy acid and about 0.1-20 wt % of alarger C₈-C₁₂ peroxy acid. An especially preferred embodiment of thecomposition includes a mixture of peroxyacetic acid and peroxyoctanoicacid. The composition may further contain about 1-15 wt % of ahydrotrope and about 5 wt-% of a chelating agent.

In other embodiments, the invention also provides a process ofcontrolling fungi and microbial plant pathogens in growing plants. Inthis embodiment, the plant is contacted with a solution made by dilutingin an aqueous liquid a concentrate containing two peroxy acids, and thefirst and second stabilizing agents described above. This mixtureincludes a smaller C₂-C₄ peroxy carboxylic acid and a larger C₈-C₁₂aliphatic peroxy carboxylic acid. An especially preferred embodiment ofthe composition includes a mixture of peroxyacetic acid and peroctanoicacid. The composition may further contain a hydrotrope and a chelatingagent. Further, the solution contains about 1-30 wt % of hydrogenperoxide. The preferred composition includes a mixture of acetic acidand octanoic acid.

The present methods can be used in the methods, processes or proceduresdescribed and/or claimed in U.S. Pat. Nos. 6,010,729, 6,103,286,6,545,047 and 8,030,351 B2 for sanitizing animal carcasses.

In some embodiments, the compositions of the present invention can beused in a method of treating animal carcasses to obtain a reduction byat least one log₁₀ in surface microbial population which method includesthe step of treating said carcass with a diluted composition of thepresent invention comprising an effective antimicrobial amountcomprising at least 2 parts per million (ppm, parts by weight per eachone million parts) of one or more peroxycarboxylic acids having up to 12carbon atoms, an effective antimicrobial amount comprising at least 20ppm of one or more carboxylic acids having up to 18 carbon atoms, andthe first and second stabilizing agents described above, to reduce themicrobial population.

In other embodiments, the present invention is directed to anantimicrobial composition adapted for cleaning and sanitizing animalcarcasses which contains about 0.5 weight percent (wt-%) to about 20wt-% of a mixture of one or more peroxycarboxylic acids having from 2-4carbon atoms, and one or more peroxycarboxylic acids having from 8-12carbon atoms, from about 0.5 wt-% to about 60 wt-% of an alpha-hydroxymono or dicarboxylic acid having 3-6 carbon atoms, an effective amountof a sequestrant, an effective amount of a hydrotrope, and the first andsecond stabilizing agents described above.

In still other embodiments, the present invention is directed to anantimicrobial composition adapted for treating animal carcassescomprising, consisting essentially of, or consisting of a mixture ofperoxyacetic and peroxyoctanoic acid in a ratio of about 10:1 to about1:1, from about 0.1 to about 10 wt-% of acetic acid, from about 4 wt-%to about 10 wt-% of hydrogen peroxide and from about 0.5 wt-% to about1.5 wt-% of a sequestering agent, and the first and second stabilizingagents described above.

In yet other embodiments, the present invention is directed to a methodof treating an animal carcass to reduce a microbial population inresulting cut meat, the method comprising the steps of spraying anaqueous antimicrobial treatment composition onto said carcass at apressure of at least 50 psi at a temperature of up to about 60° C.resulting in a contact time of at least 30 seconds, the antimicrobialcomposition comprising an effective antimicrobial amount comprisingleast 2 ppm of one or more carboxylic acid, peroxycarboxylic acid ormixtures thereof, and the first and second stabilizing agents describedabove; and achieving at least a one log₁₀ reduction in the microbialpopulation.

In yet other embodiments, the present invention is directed to a methodof treating an animal carcass to reduce a microbial population inresulting cut meat, the method comprising the steps of placing theanimal carcass in a chamber at atmospheric pressure; filling the chamberwith condensing steam comprising an antimicrobial composition, e.g., adiluted composition of the present invention, for a short duration; andquickly venting and cooling the chamber to prevent browning of the meatcarcass; wherein the duration of the steam thermal process may be fromabout 5 seconds to about 30 seconds and the chamber temperature mayreach from about 50° C. to about 93° C.

The antimicrobial composition can be applied in various ways to obtainintimate contact with each potential place of microbial contamination.For example, it can be sprayed on the carcasses, or the carcasses can beimmersed in the composition. Additional methods include applying afoamed composition and a thickened or gelled composition. Vacuum and orlight treatments can be included, if desired, with the application ofthe antimicrobial composition. Thermal treatment can also be applied,either pre-, concurrent with or post application of the antimicrobialcomposition.

One preferred spray method for treating carcasses with dilutedcompositions of the present invention involves spraying the carcass withan aqueous spray at a temperature less than about 60° C. at a pressureof about 50 to 500 psi gauge wherein the spray comprises an effectiveantimicrobial amount of a carboxylic acid, an effective antimicrobialamount of a peroxycarboxylic acid or mixtures thereof, and the first andsecond stabilizing agents described above. These sprays can also containan effective portion of a peroxy compound such as hydrogen peroxide andother ingredients such as sequestering agents, etc. The high pressurespray action of the aqueous treatment can remove microbial populationsby combining the mechanical action of the spray with the chemical actionof the antimicrobial materials to result in an improved reduction ofsuch populations on the surface of the carcass.

All pressures are psig (or psi gauge). In some embodiments,differentiation of antimicrobial “-cidal” or “-static” activity, thedefinitions which describe the degree of efficacy, and the officiallaboratory protocols for measuring this efficacy are importantconsiderations for understanding the relevance of antimicrobial agentsin compositions. Antimicrobial compositions may effect two kinds ofmicrobial cell damages. The first is a truly lethal, irreversible actionresulting in complete microbial cell destruction or incapacitation. Thesecond type of cell damage is reversible, such that if the organism isrendered free of the agent, it can again multiply. The former is termedbacteriocidal and the latter, bacteriostatic. A sanitizer and adisinfectant are, by definition, agents which provide antibacterial orbacteriocidal activity and achieve at least a five-fold reduction (i.e.,a five log 10 reduction) in microbial populations after a 30 secondcontact time (see AOAC method 960.09).

The present methods can be used in the methods, processes or proceduresdescribed and/or claimed in U.S. Pat. Nos. 8,017,409 and 8,236,573. Insome embodiments, the present methods may be used for a variety ofdomestic or industrial applications, e.g., to reduce microbial or viralpopulations on a surface or object or in a body or stream of water. Thediluted (or use) compositions of the present invention may be applied ina variety of areas including kitchens, bathrooms, factories, hospitals,dental offices and food plants, and may be applied to a variety of hardor soft surfaces having smooth, irregular or porous topography. Suitablehard surfaces include, for example, architectural surfaces (e.g.,floors, walls, windows, sinks, tables, counters and signs); eatingutensils; hard-surface medical or surgical instruments and devices; andhard-surface packaging. Such hard surfaces may be made from a variety ofmaterials including, for example, ceramic, metal, glass, wood or hardplastic. Suitable soft surfaces include, for example paper; filtermedia, hospital and surgical linens and garments; soft-surface medicalor surgical instruments and devices; and soft-surface packaging. Suchsoft surfaces may be made from a variety of materials including, forexample, paper, fiber, woven or non-woven fabric, soft plastics andelastomers. The diluted (or use) compositions may also be applied tosoft surfaces such as food and skin (e.g., a hand). The diluted (or use)compositions may be employed as a foaming or non-foaming environmentalsanitizer or disinfectant.

In other embodiments, the diluted (or use) compositions of the presentinvention may be included in products such as sterilants, sanitizers,disinfectants, preservatives, deodorizers, antiseptics, fungicides,germicides, sporicides, virucides, detergents, bleaches, hard surfacecleaners, hand soaps, waterless hand sanitizers, and pre- orpost-surgical scrubs.

In still other embodiments, the diluted (or use) compositions of thepresent invention may also be used in veterinary products such asmammalian skin treatments or in products for sanitizing or disinfectinganimal enclosures, pens, watering stations, and veterinary treatmentareas such as inspection tables and operation rooms. The diluted (oruse) compositions may be employed in an antimicrobial foot bath forlivestock or people.

In yet other embodiments, the present methods may be employed forreducing the population of pathogenic microorganisms, such as pathogensof humans, animals, and the like. Exemplary pathogenic microorganismsinclude fungi, molds, bacteria, spores, and viruses, for example, S.aureus, E. coli, Streptococci, Legionella, Pseudomonas aeruginosa,mycobacteria, tuberculosis, phages, or the like. Such pathogens maycause a varieties of diseases and disorders, including Mastitis or othermammalian milking diseases, tuberculosis, and the like. The presentmethods may be used to reduce the population of microorganisms on skinor other external or mucosal surfaces of an animal. In addition, thepresent methods may be used to kill pathogenic microorganisms thatspread through transfer by water, air, or a surface substrate. In someapplications, the diluted (or use) compositions of the present inventionneed only be applied to the skin, other external or mucosal surfaces ofan animal water, air, or surface.

In yet other embodiments, the present methods may also be used on foodsand plant species to reduce surface microbial populations; used atmanufacturing or processing sites handling such foods and plant species;or used to treat process waters around such sites. For example, thepresent methods may be used on food transport lines (e.g., as beltsprays); boot and hand-wash dip-pans; food storage facilities;anti-spoilage air circulation systems; refrigeration and coolerequipment; beverage chillers and warmers, blanchers, cutting boards,third sink areas, and meat chillers or scalding devices. The presentmethods may be used to treat transport waters such as those found influmes, pipe transports, cutters, slicers, blanchers, retort systems,washers, and the like. Particular foodstuffs that may be treated withthe present methods include eggs, meats, seeds, leaves, fruits andvegetables. Particular plant surfaces include both harvested and growingleaves, roots, seeds, skins or shells, stems, stalks, tubers, corms,fruit, and the like. The present methods may also be used to treatanimal carcasses to reduce both pathogenic and non-pathogenic microbiallevels.

In yet other embodiments, the present methods may be useful in thecleaning or sanitizing of containers, processing facilities, orequipment in the food service or food processing industries. The presentmethods may be used on food packaging materials and equipment, includingfor cold or hot aseptic packaging. Examples of process facilities inwhich the present methods may be employed include a milk line dairy, acontinuous brewing system, food processing lines such as pumpable foodsystems and beverage lines, etc. Food service wares may be disinfectedwith the present methods. For example, the present methods may also beused on or in ware wash machines, dishware, bottle washers, bottlechillers, warmers, third sink washers, cutting areas (e.g., waterknives, slicers, cutters and saws) and egg washers. Particular treatablesurfaces include packaging such as cartons, bottles, films and resins;dish ware such as glasses, plates, utensils, pots and pans; ware washmachines; exposed food preparation area surfaces such as sinks,counters, tables, floors and walls; processing equipment such as tanks,vats, lines, pumps and hoses (e.g., dairy processing equipment forprocessing milk, cheese, ice cream and other dairy products); andtransportation vehicles. Containers include glass bottles, PVC orpolyolefin film sacks, cans, polyester, PEN or PET bottles of variousvolumes (100 ml to 2 liter, etc.), one gallon milk containers, paperboard juice or milk containers, etc.

In yet other embodiments, the present methods may also be used on or inother industrial equipment and in other industrial process streams suchas heaters, cooling towers, boilers, retort waters, rinse waters,aseptic packaging wash waters, and the like. The present methods may beused to treat microbes and odors in recreational waters such as inpools, spas, recreational flumes and water slides, fountains, and thelike.

In yet other embodiments, a filter containing the diluted (or use)compositions of the present invention may be used to reduce thepopulation of microorganisms in air and liquids. Such a filter may beused to remove water and air-born pathogens such as Legionella.

In yet other embodiments, the present methods may be employed forreducing the population of microbes, fruit flies, or other insect larvaon a drain or other surface.

In yet other embodiments, the present methods may also be employed bydipping food processing equipment into the diluted (or use) compositionor solution of the present invention, soaking the equipment for a timesufficient to sanitize the equipment, and wiping or draining excesscomposition or solution off the equipment. The present methods may befurther employed by spraying or wiping food processing surfaces with theuse composition or solution, keeping the surfaces wet for a timesufficient to sanitize the surfaces, and removing excess composition orsolution by wiping, draining vertically, vacuuming, etc.

In yet other embodiments, the present methods may also be used forsanitizing hard surfaces such as institutional type equipment, utensils,dishes, health care equipment or tools, and other hard surfaces. Thepresent methods may also be employed in sanitizing clothing items orfabrics which have become contaminated. The diluted (or use)compositions of the present invention can be contacted with anycontaminated surfaces or items at use temperatures in the range of about4° C. to 60° C., for a period of time effective to sanitize, disinfect,or sterilize the surface or item. For example, the diluted (or use)compositions may be injected into the wash or rinse water of a laundrymachine and contacted with contaminated fabric for a time sufficient tosanitize the fabric. Excess composition may be removed by rinsing orcentrifuging the fabric.

In yet other embodiments, the diluted (or use) compositions of thepresent invention may be applied to microbes or to soiled or cleanedsurfaces using a variety of methods. These methods may operate on anobject, surface, in a body or stream of water or a gas, or the like, bycontacting the object, surface, body, or stream with the diluted (oruse) composition. Contacting may include any of numerous methods forapplying a composition, such as spraying the composition, immersing theobject in the composition, foam or gel treating the object with thecomposition, or a combination thereof.

In yet other embodiments, the diluted (or use) compositions of thepresent invention may be employed for bleaching pulp. The compositionsmay be employed for waste treatment. Such a composition may includeadded bleaching agent.

In yet other embodiments, other hard surface cleaning applications forthe diluted (or use) compositions of the present invention includeclean-in-place systems (CIP), clean-out-of-place systems (COP),washer-decontaminators, sterilizers, textile laundry machines, ultra andnano-filtration systems and indoor air filters. COP systems may includereadily accessible systems including wash tanks, soaking vessels, mopbuckets, holding tanks, scrub sinks, vehicle parts washers,non-continuous batch washers and systems, and the like.

The concentrations of peracid and/or hydrogen peroxide in the diluted(or use) compositions of the present invention can be monitored in anysuitable manner. In some embodiments, the concentrations of peracidand/or hydrogen peroxide in the diluted (or use) compositions can bemonitored using a kinetic assay procedure, e.g., the exemplary proceduredisclosed in U.S. Pat. Nos. 8,017,409 and 8,236,573. This can beaccomplished by exploiting the difference in reaction rates betweenperacid and hydrogen peroxide when using, for example, a buffered iodidereagent to differentiate peracid and hydrogen peroxide concentrationswhen both these analyte compounds are present in the use composition.The use composition monitor may also determine the concentrations ofperacid and/or hydrogen peroxide in the presence of other additionalingredients, such as acidulants, one or more stabilizing agents,nonionic surfactants, semi-polar nonionic surfactants, anionicsurfactants, amphoteric or ampholytic surfactants, adjuvants, solvents,additional antimicrobial agents or other ingredients which may bepresent in the use composition.

In some embodiments, exemplary compositions of the present inventioncomprise the components set forth in the following Tables 1-3. Prior toor during use, the exemplary compositions can be diluted to a desiredlevel. For example, the exemplary compositions can be diluted by 2, 5,10, 50, 100, 500, 1,000, 5,000, or 10,000 folds.

TABLE 1 Vortexx ES with DPA Formula (pre-equilibrium) Acetic Acid 59.00%Octanoic Acid 10.00% Hydrogen Peroxide (35%) 30.00% DPA (100%) 0.04%HEDP (60%) 0.96% Water 0.00% Total 100.00% Equilibrium ConcentrationsAcetic Acid 48.54% Peracetic Acid 13.25% Octanoic Acid 8.74% PeroctanoicAcid 1.40% Hydrogen Peroxide 4.00% DPA (100%) 0.04% HEDP 0.58% Water23.45% Total 100.00%

TABLE 2 KX-6145 (Inspexx 100) Formula (pre-equilibrium) Acetic Acid55.00% Octanoic Acid 4.00% Hydrogen Peroxide (35%) 30.00% DPA (100%)0.04% HEDP (60%) 1.00% Water 9.96% Total 100.00% EquilibriumConcentrations Acetic Acid 45.53% Peracetic Acid 12.00% Octanoic Acid3.28% Peroctanoic Acid 0.80% Hydrogen Peroxide 6.20% DPA 0.04% HEDP0.60% Water 31.55% Total 100.00%

TABLE 3 Tsunami 200 (Falcon 15AO) Formula (pre-equilibrium) Acetic Acid53.96% Octanoic Acid 15.00% Hydrogen Peroxide (35%) 30.00% DPA (100%)0.04% HEDP (60%) 1.00% Water 0.00% Total 100.00% EquilibriumConcentrations Acetic Acid 43.93 Peracetic Acid 12.75% Octanoic Acid12.75% Peroctanoic Acid 2.50% Hydrogen Peroxide 4.25% DPA 0.04% HEDP0.60% Water 23.18% Total 100.00%

F. METHODS FOR REDUCING THE LEVEL OF HYDROGEN SULFIDE

In yet another aspect, the present invention is directed to a method forreducing the level of hydrogen sulfide (H2S), hydrosulfuric acid or asalt thereof in a water source, which method comprises a step ofcontacting a water source with a composition in a diluted level to forma treated water source, wherein said composition comprises:

-   -   1) a C₁-C₂₂ carboxylic acid;    -   2) a C₁-C₂₂ percarboxylic acid;    -   3) hydrogen peroxide;    -   4) a first stabilizing agent, which is a picolinic acid or a        compound having the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —R^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

-   -   or a salt thereof;    -   or a compound having the following Formula (IB):

wherein

R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

-   -   6) a second stabilizing agent, which is a compound having the        following Formula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof; and

wherein said hydrogen peroxide has a concentration of at least about 0.1wt-%, the C₁-C₂₂ percarboxylic acid has a concentration of at leastabout 2 times of the concentration of said hydrogen peroxide, and saidcomposition has a pH at about 4 or less, and

wherein said treated water source comprises from about 1 ppm to about10,000 ppm of said C₁-C₂₂ percarboxylic acid, and said contacting steplasts for sufficient time to stabilize or reduce the level of H₂S,hydrosulfuric acid or a salt thereof in said treated water source.

In some embodiments, the composition used in the present methods is anequilibrated composition that comprises peracid, hydrogen peroxide,carboxylic acid and a solvent, e.g., water.

In some embodiments, the composition used in the present methods doesnot comprise a mineral acid, e.g., the mineral acids disclosed in WO91/07375.

The composition used in the present methods can comprise any suitablelevel of the hydrogen peroxide. In some embodiments, the hydrogenperoxide in the equilibrated composition has a concentration of about0.1% to about 15%, e.g., about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%,0.8%, 0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%,or 15%. Prior to or during use, the exemplary compositions can bediluted to a desired level.

The composition used in the present methods can comprise any suitablelevel of the C₁-C₂₂ percarboxylic acid relative to the level of thehydrogen peroxide. In some embodiments, the C₁-C₂₂ percarboxylic acidhas a concentration of at least about 6 times of the concentration ofthe hydrogen peroxide. In other embodiments, the C₁-C₂₂ percarboxylicacid has a concentration of at least about 10 times of the concentrationof the hydrogen peroxide. In still other embodiments, the C₁-C₂₂percarboxylic acid has a concentration of at least about 2, 3, 4, 5, 6,7, 8, 9 or 10 times of the concentration of the hydrogen peroxide.

Any suitable C₁-C₂₂ percarboxylic acid can be used in the presentmethods. In some embodiments, the C₁-C₂₂ percarboxylic acid is a C₂-C₂₀percarboxylic acid. In other embodiments, the C₁-C₂₂ percarboxylic acidcomprises peroxyacetic acid, peroxyoctanoic acid and/or peroxysulfonatedoleic acid. Other exemplary C₁-C₂₂ percarboxylic acids are described inthe above Section B. The composition used in the present methods cancomprise any suitable level of the C₁-C₂₂ percarboxylic acid andhydrogen peroxide. In some embodiments, the C₁-C₂₂ percarboxylic acid inthe equilibrated composition has a concentration from about 0.1% toabout 30%, e.g., about 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%,0.9%, 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%,16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, 26%, 27%, 28%, 29%, or30%. Prior to or during use, the exemplary compositions can be dilutedto a desired level.

Any suitable first stabilizing agent can be used in the composition usedin the present methods. In some embodiments, the first stabilizing agentis a picolinic acid, or a salt thereof. In other embodiments, the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.The first stabilizing agent can be used at any suitable concentration.In some embodiments, the first stabilizing agent has a concentrationfrom about 0.005 wt-% to about 5 wt-%. In other embodiments, the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%. In still other embodiments, the first stabilizing agent has aconcentration at about 0.005 wt-%, 0.01 wt-%, 0.1 wt-%, 1 wt-%, 2 wt-%,3 wt-%, 4 wt-%, or 5 wt-%. In yet other embodiments, the firststabilizing agent has a concentration at about 0.05 wt-%, 0.06 wt-%,0.07 wt-%, 0.08 wt-%, 0.09 wt-%, 0.10 wt-%, 0.11 wt-%, 0.12 wt-%, 0.13wt-%, 0.14 wt-%, or 0.15 wt-%.

Any suitable second stabilizing agent can be used in the presentcompositions. In some embodiments, the second stabilizing agent is1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP), or a salt thereof.The second stabilizing agent can be used at any suitable concentration.In some embodiments, the second stabilizing agent has a concentrationfrom about 0.1 wt-% to about 10 wt-%, e.g., 0.1 wt-%, 0.5 wt-%, 1 wt-%,2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%, or 10wt-%. In other embodiments, the second stabilizing agent has aconcentration from about 0.5 wt-% to about 5 wt-%, e.g., 0.5 wt-%, 1wt-%, 1.5 wt-%, 2 wt-%, 2.5 wt-%, 3 wt-%, 3.5 wt-%, 4 wt-%, 4.5 wt-% or5 wt-%. In still other embodiments, the second stabilizing agent has aconcentration from about 0.6 wt-% to about 1.8 wt-%, e.g., 0.6 wt-%, 0.7wt-%, 0.8 wt-%, 0.9 wt-%, 1.0 wt-%, 1.1 wt-%, 1.2 wt-%, 1.3 wt-%, 1.4wt-%, 1.5 wt-%, 1.6 wt-%, 1.7 wt-%, or 1.8 wt-%.

In some embodiments, the first stabilizing agent is a2,6-pyridinedicarboxylic acid, or a salt thereof, and the secondstabilizing agent is HEDP, or a salt thereof.

The composition used in the present methods can retain any suitablelevel or percentage of the C₁-C₂₂ percarboxylic acid activity for anysuitable time after the treated target composition is formed. In someembodiments, the present composition retains at least about 50%, 55%,60%, 65%, 70%, 75%, 80%, 85% or 90% of the initial C₁-C₂₂ percarboxylicacid activity for any suitable time after the treated target compositionis formed. In other embodiments, the present composition retains atleast about 60% of the initial C₁-C₂₂ percarboxylic acid activity for atleast 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 20, 25, 30minutes, 1, 2, 5, 10, 15, 20 or 24 hours, or longer after the treatedtarget composition is formed.

In some embodiments, the composition used in the present methods cancomprise a peroxidase or a catalase to further reduce the hydrogenperoxide concentration. Any suitable peroxidase or a catalase can beused in the present compositions. Exemplary peroxidases and catalasesare described in the above Section B. In other embodiments, thecomposition used in the present methods can further comprise a substancethat aids solubilization of the first and/or second stabilizingagent(s). Exemplary substances that can aid solubilization of the firstand/or second stabilizing agent(s) include hydrotropes such as sodiumxylene sulfonate, sodium cumene sulfonates, and surfactants, such asanionic surfactants and noinionic surfactants.

The treated water source can comprise any suitable level of the C₁-C₂₂percarboxylic acid. In some embodiments, the treated water sourcecomprises from about 10 ppm to about 1,000 ppm of the C₁-C₂₂percarboxylic acid, e.g., about 10 ppm, 20 ppm, 30 ppm, 40 ppm, 50 ppm,60 ppm, 70 ppm, 80 ppm, 90 ppm, 100 ppm, 110 ppm, 120 ppm, 130 ppm, 140ppm, 150 ppm, 160 ppm, 170 ppm, 180 ppm, 190 ppm, 200 ppm, 300 ppm, 400ppm, 500 ppm, 600 ppm, 700 ppm, 800 ppm, 900 ppm, or 1,000 ppm of theC₁-C₂₂ percarboxylic acid.

The treated water source can comprise any suitable C₁-C₂₂ percarboxylicacid. In some embodiments, the treated target composition comprisesperoxyacetic acid, peroxyoctanoic acid and/or peroxysulfonated oleicacid.

The treated water source can comprise any suitable level of the hydrogenperoxide. In some embodiments, the treated water source comprises fromabout 1 ppm to about 15 ppm of the hydrogen peroxide, e.g., about 1 ppm,2 ppm, 3 ppm, 4 ppm, 5 ppm, 6 ppm, 7 ppm, 8 ppm, 9 ppm, 10 ppm, 11 ppm,12 ppm, 13 ppm, 14 ppm, or 15 ppm of the hydrogen peroxide.

The treated water source can comprise any suitable level of the C₁-C₂₂percarboxylic acid relative to the level of the hydrogen peroxide. Insome embodiments, the treated water source comprises the C₁-C₂₂percarboxylic acid that has a concentration of at least about 2, 3, 4,5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19 or 20 times of theconcentration of the hydrogen peroxide.

The treated water source can comprise any suitable first stabilizingagent and second stabilizing agent. In some embodiments, the treatedwater source comprises a first stabilizing agent that is a2,6-pyridinedicarboxylic acid, or a salt thereof, and a secondstabilizing agent that is HEDP, or a salt thereof.

The treated water source can retain any suitable level of the initialC₁-C₂₂ percarboxylic acid activity for any suitable time. In someembodiments, the treated water source retains at least about 50%, 60%,70%, 80%, 90%, 95%, 99%, or 100% of the initial C₁-C₂₂ percarboxylicacid activity for any suitable time. In other embodiments, the treatedwater source retains a suitable level of the initial C₁-C₂₂percarboxylic acid activity for at least 1 minute, 2 minutes, 3 minutes,4 minutes, 5 minutes, 6 minutes, 7 minutes, 8 minutes, 9 minutes, 10minutes, 11 minutes, 12 minutes, 13 minutes, 14 minutes, or 15 minutesafter the treated target composition is formed. In still otherembodiments, the treated water source retains at least about 60% of theinitial C₁-C₂₂ percarboxylic acid activity for 15 minutes after thetreated water source is formed.

The contacting step can last for any suitable time. In some embodiments,the contacting step lasts for at least 10 seconds, 20 seconds, 30seconds, 40 seconds, 50 seconds, 1 minute, 10 minutes, 30 minutes, 1hour, 2 hours, 4 hours, 8 hours, 16 hours, 1 day, 3 days, 1 week, orlonger.

The present methods can be used for reducing the level of hydrogensulfide (H2S), hydrosulfuric acid or a salt thereof in any suitablewater source. Exemplary water source includes fresh water, pond water,sea water, produced water and a combination thereof. The water sourcecan comprise any suitable level of produced water, e.g., at least about1 wt-%, 2 wt-%, 3 wt-%, 4 wt-%, 5 wt-%, 6 wt-%, 7 wt-%, 8 wt-%, 9 wt-%,10 wt-%, 20 wt-%, 30 wt-%, 40 wt-%, 50 wt-%, 60 wt-%, 70 wt-%, 80 wt-%,90 wt-%, or more produced water.

The present methods can be used for reducing the level of hydrogensulfide (H2S), hydrosulfuric acid or a salt thereof in a water source byany suitable degree. For example, the level of H2S, hydrosulfuric acidor a salt thereof in the treated water source can be reduced by at least10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, 95%, 99%, or more from theuntreated level.

The present methods can be used for reducing the level of hydrogensulfide (H2S), hydrosulfuric acid or a salt thereof in a water sourcefrom any suitable location. For example, the present methods can be usedfor reducing the level of hydrogen sulfide (H2S), hydrosulfuric acid ora salt thereof in a water source partially or completely obtained orderived from a subterranean environment, e.g., an oil or a gas well.

In some embodiments, the present methods can further comprise directingthe treated water source into a subterranean environment, e.g., an oilor a gas well, or disposing of the treated water source.

G. EXAMPLES

The following examples are included for illustrative purposes only andare not intended to limit the scope of the invention.

Example 1. Stability Comparison of Peracetic Acid Compositions withVarious Stabilizers

Peracetic acid (POAA) compositions with various stabilizers as describedin Table 1 were made, and on reaching equilibrium, the compositions werestored in 50° C. oven. The level of peracetic acid and hydrogen peroxidewere monitored by an iodometric titration method. The results aresummarized in Table 4 and FIG. 1.

TABLE 4 Peracetic acid compositions with various stabilizers ComponentComposition I-A Composition I-B Composition I-C Acetic acid 83.0% 83.9%82.9% H2O2 (50%) 16.0% 16.0% 16.0% HEDP (60%)  1.0%  0.0%  1.0%Dipicolinic  0.0%  0.1%  0.1% acid (DPA) Total 100.0%  100.0%  100.0% POAA (after 12.12%  13.55%  14.37%  equilibrium) H2O2 (after 1.09% 1.65%1.26% equilibrium)

As can be seen in Table 4, after reaching equilibrium, the level ofperacetic acid formed among compositions are in the order ofI-C>I-B>I-A. While not wishing to be bound by any particular theories,it is thought that this difference in level of peracetic acid formed isdue to the different efficiency of the stabilizers in the compositions.Once formed, peracetic acid starts to decompose, and the stabilizer inthe composition will have a direct impact on the decomposition rate ofthe peracetic acid. Thus, the more efficient the stabilizer, the lessdecomposition will occur in the compositions, and more peracetic acidwill be formed upon reaching equilibrium. This is important not only inmaintaining the shelf life of a peracetic acid composition, but it isalso economically beneficial to be able to form higher levels ofperacetic acid in compositions from the same level of starting materials(e.g., acetic acid, and hydrogen peroxide).

TABLE 5 Stability of Peracetic Acid Compositions with VariousStabilizers Time Composition I-A Composition I-B Composition I-C (day)POAA % H₂O₂ % POAA % H₂O₂ % POAA % H₂O₂ % 0 12.12 1.09 13.55 1.65 14.371.26 7 4.84 0.36 13.43 1.20 14.18 1.33 14 na na na na 14.11 1.26 21 0.130.0 11.93 1.06 14.00 1.30 28 0.0 0.0 10.97 1.01 13.95 1.25 35 0.0 0.010.23 0.88 13.74 1.28 42 0.0 0.0  9.44 0.90 13.65 1.23

As can be seen from Table 5 and FIG. 1, a synergistic stabilizationeffect was observed when a combination of HEDP and DPA was used in theperacetic acid formulations. Surprisingly, it was found that for thehigh ratio peracetic acid to hydrogen peroxide compositions tested, themost commonly used stabilizer, i.e., HEDP, had only marginal effects onthe stabilization of the peracetic acid. For example, as shown in Table2, composition I-A lost more than 60% of the peracetic acid formed afteronly 1 week under the test conditions. Composition I-B, which used onlyDPA as a stabilizer, had an improved stabilization effect compared tocomposition I-A, and lost about 20% peracetic acid in four weeks underthe tested conditions. In contrast, the combination of DPA and HEDPproved to be excellent stabilizer for the high ratio peracetic acid tohydrogen peroxide compositions tested. As shown in Table 2, CompositionI-C, which had a combination of HEDP and DPA as stabilizers, lost lessthan 5% peracetic acid in 4 weeks under the same test conditions. Thestability effect of the combination of HEDP and DPA is more than the sumof the individual stability effect of HEDP and DPA. This resultdemonstrates that the stability effect of the combination of HEDP andDPA is a synergistic stabilization effect, and not a merely additiveeffect of the individual stability effect of HEDP and DPA.

Example 2. Synergistic Stabilization Study of HEDP and DPA in High RatioPeracetic Acid to Hydrogen Peroxide (POAA/H₂O₂) Compositions

To systematically study the synergistic stabilization performance ofHEDP and DPA, high ratio POAA/H₂O₂ peracetic acid compositions withvarious stabilizers are made as described in Table 6. The compositions,once equilibrium was reached, were stored in a 50° C. oven, and thelevel of peracetic acid and hydrogen peroxide were monitored by aniodometric titration method. The results are summarized in Table 7.

TABLE 6 Peracetic Acid Compositions with Various Stabilizers ComponentIIA-1 IIA-2 IIA-3 IIA-4 IIA-5 Acetic acid 83.0% 82.0% 83.0% 83.0% 79.0%H2O2 (50%) 16.01%  16.01%  16.01%  16.01%  16.02%  HEDP (60%) 1.00%2.00% 3.01% 4.02% 5.00% DPA 0.00% 0.00% 0.00% 0.00% 0.00% Total 100% 100%  100%  100%  100% POAA % (equilibrium) 11.60 11.63 11.68 11.8811.80 H2O2 (equilibrium)  0.84  0.91  0.95  0.95  1.03 Component IIB-1IIB-2 IIB-3 IIB-4 IIB-5 Acetic acid 83.88%  83.93%  83.93%  83.94% 83.96%  H2O2 (50%) 16.02%  16.00%  16.02%  16.02%  16.00%  HEDP (60%)0.00% 0.00% 0.00%  0.00% 0.00% DPA 0.12% 0.10% 0.08% 0.06% 0.04% Total100%  100%  100%  100%  100% POAA % (equilibrium) 13.90 14.01 13.9714.15 14.05 H2O2 (equilibrium)  1.15  1.21  1.29  1.28  1.20 ComponentIIC-1 IIC-2 IIC-3 IIC-4 IIC-5 IIC-6 Acetic acid 84.03%  82.90%  81.90% 80.92%  79.95%  78.97%  H2O2 (50%) 16.02%  16.00%  16.04%  16.02% 16.01%  16.01%  HEDP (60%) 0.00% 1.00% 2.01% 3.01% 4.01% 5.00% DPA 0.00%0.12% 0.10% 0.08% 0.06% 0.04% Total  100%  100%  100%  100%  100%  100%POAA % (equilibrium) 11.42 14.51 14.39 14.30 14.18 13.43 H2O2(equilibrium)  0.82  1.20  1.16  1.17  1.23  1.22

TABLE 7 Peracetic Acid (POAA) Stability at 50° C. Time 42 Compositions 0days 7 days 14 days 21 days 28 days days IIA-1 (POAA %) 11.60 4.45 0.440.03 0.00 0.00 IIA-2 (POAA %) 11.63 5.03 0.98 0.19 0.03 0.00 IIA-3 (POAA%) 11.68 5.11 1.96 0.47 0.10 0.00 IIA-4 (POAA %) 11.88 6.24 2.58 0.830.24 0.00 IIA-5 (POAA %) 11.80 6.57 3.03 1.07 0.34 0.00 IIB-1 (POAA %)13.90 13.02 12.15 11.22 10.22 8.32 IIB-2 (POAA %) 14.01 13.16 12.1611.12 10.21 8.06 IIB-3 (POAA %) 13.97 13.10 12.00 10.96 10.00 7.82 IIB-4(POAA %) 14.15 13.26 12.25 11.16 10.12 7.92 IIB-5 (POAA %) 14.05 13.0411.96 10.88 9.63 7.36 IIC-1 (POAA %) 11.42 2.35 0.05 0.00 0.00 0.00IIC-2 (POAA %) 14.51 14.47 14.13 13.99 13.98 13.76 IIC-3 (POAA %) 14.3914.28 13.99 13.83 13.81 13.54 IIC-4 (POAA %) 14.30 14.19 14.20 13.9313.88 13.21 IIC-5 (POAA %) 14.18 14.06 13.94 13.96 13.66 13.29 IIC-6(POAA %) 13.43 13.96 13.97 13.81 13.63 12.94

The results shown in Table 7 clearly indicate that when a singlestabilizer is used, simply increasing the levels of stabilizer in thecomposition will not proportionally increase the stability of theperacetic aid. For example, for composition series IIA, increasing HEDPfrom 1 to 5% resulted in only a marginal increase of stability. Forcomposition series JIB, increasing the level of DPA beyond 0.06% hadvirtually no impact on the stability. Without wishing to be bound by anyparticular theory, it is thought that stabilizers in peracidcompositions stabilize peracids through the chelating of the tracetransitional metal ions in the compositions. Thus, the efficacy of astabilizer is mainly dependent on its binding constant (Ksp) with theindividual ion. Therefore, it is thought that increasing theconcentration of a single stabilizer has a very limited effect on thebinding capability of that stabilizer.

While not wishing to be bound by any particular theory, on one hand itis thought that the combination of two stabilizers, such as HEDP and DPAmay form mixed ligand complexes with transition metals with an increasedbinding constant (Ksp) compared with that of the individual ligand metalcomplex formed when a single stabilizer is used. This mixed ligandcomplex is thought to lead to the significant increase in stabilizingeffect seen when using a combination of stabilizers. On the other hand,DPA and the related niacin compounds are known hydroxyl radicalscavengers (see for example: Biosci. Biotechnol. Biochem., 2002, 66(3),641-645.), and by quenching the hydroxyl radicals formed and thuspreventing the subsequent chain decomposition reaction involving theperacid species, the stability of the corresponding peracid compositionwill be further improved.

FIG. 2 further illustrates the synergistic stabilizing capability ofHEDP and DPA. The percent of POAA retained at the end of 28 days(compared to 0 days) at 50° C. of composition TIC series, which had amixture of HEDP and DPA, was compared with the sum of percent of POAAretained from the composition IIA (HEDP only as a stabilizer) and IIBseries (DPA only as a stabilizer). For example, composition IIC-2, whichcontains 1.2% HEDP and 1,200 ppm DPA stabilizers, retained 96% POAA; incontrast, composition IIA-2 which contains 1.2% HEDP as singlestabilizer, retained 0.26% POAA; and composition which contains 1,200ppm DPA as single stabilizer, retained 73.5% POAA. Combined,compositions IIA-2 and have the same stabilizer as IIC-2, but the sum ofPOAA retained from IIA-2 and is only 73.8%, much less than that ofIIC-2. While not wishing to be bound by any particular theories, thecombination of two different types of ligands, such as HEDP and DPA, mayform mixed ligand complexes with the transition metals thatcatalytically decompose peracids, and the mixed ligand complexes formedhave dramatically increased binding constant (Ksp) comparing with thatof the individual ligand metal complex. The increased transition metalbinding efficiency by the mixture of HEDP and DPA thus contributed tothe synergistic stabilization capability of peracids.

Example 3. Self-Accelerating Decomposition Testing of Low HydrogenPeroxide Peroxyacetic Acid Chemistries

The following SADT procedure is a standardized United Nations protocolto help determine the hazard classes of self-heating substances known asthe “H4 method” (sect. 28.4.4, p. 314, UN “Recommendations on theTransport of Dangerous Goods, Manual of Tests and Criteria”, 5^(th)revised edition (2009).) The method is specific to the type of packagingused, and if the SADT temperature is found to be 45 degrees C. or lower,the product must be shipped, stored and used with rigorous refrigeratedcontrols. Such temperature controlled requirements make it impracticalto ship, and store the products. The self-heating behavior ofchemistries in very large package sizes can be simulated in Dewar flaskswhich have previously been tested to determine that they closely reflectthe heat transfer properties of the packaging to be used with thechemicals. Bulk tanks are the largest potential package sizes and tomodel their heat transfer properties it is recommended to use sphericalDewar flasks. The UN committee for transport of Dangerous Goods furtherbuilds a safety margin into the 300 gallon and larger package sizes byrequiring that they have SADT's≥50 deg C. As per UN-H4 guidelines28.4.1.4.1, if the temperature of the contents within the flasks doesnot exceed the oven temperature by greater than 6 degrees C. within 7days, the SADT by definition is greater than the oven temperature. Theguidelines further define the zero time as when the sample temperatureis within 2 degrees of the oven temperature and require an 80% filledDewar fitted with temperature monitoring and vented closures.

For this experiment, the above test conditions were used, and threespherical Dewar flasks were filled to 80% of full with chemistries I-A,I-B, and IC (See Table 8).

TABLE 8 Formula Formula Formula Component I-A I-B I-C Acetic acid 83.0083.96 82.96 Hydrogen peroxide (50%) 16.00 16.00 16.00 Dequest 2010 (60%HEDP) 1.00 0.00 1.00 Dipicolinic acid (DPA) 0.00 0.10 0.10 Total 100.00100.00 100.00

As can be seen in FIG. 3, chemistry I-A and I-B containing respectivelyHEDP only, and DPA only, as stabilizers exceeded the 6 degree exothermlimit within 1.5 days and 3 days respectively. The same concentrationsof HEDP and DPA when mixed however produced such an increasedstabilization such that the self-heating effects were not sufficient toreach the oven temperature within the 7 day period. Thus, thiscombination of stabilizers used with this peracid composition wouldallow for the bulk storage and transport of the peracid compositionwithout refrigeration.

The above examples are included for illustrative purposes only and arenot intended to limit the scope of the invention. Many variations tothose described above are possible. Since modifications and variationsto the examples described above will be apparent to those of skill inthis art, it is intended that this invention be limited only by thescope of the appended claims.

Example 4. Use Solution Peracetic Acid (POAA) Stability Comparison

The use solution stability is a very important factor in evaluating theperformance of a biocide, especially for water treatment application. Itis preferred that the biocide is stable during the time period oftreatment, as less biocide will be needed for the application and thusare economically and environmentally beneficial. Peroxycarboxylic acidsare less susceptible to decomposition than most oxidative biocides, suchas halogen based biocides. However, as strong oxidation agents, thestability of peroxycarboxylic acids in use solution are stronglydependent on the water conditions, such as contaminants and pH of thewater. This is especially apparent in the case of impure ground watersrelated to oil or gas fracking operations. In order to conserve thewater used on fracking sites, the water is partially recovered andrecycled at each site. While it is uncertain what component of the usedfracking water might be responsible for quenching the peracetic acid, itis a critical shortcoming for commercial peracetic acid as it greatlyaffects the cost and antimicrobial ability of this preferred biocide.This experiment is designed to assess the use solution stability ofvarious peracetic acid compositions in water which contains the reusedwater from oil and gas fracking applications.

The water used in this test contains 20% (volume) of used water from twooil and gas well fracking sites respectively, and 80% (volume) freshwater. The peracetic acid compositions tested includes a commercialperacetic acid composition (around 15% POAA, 10% H₂O₂) currently used asa biocide for oil and gas well water treatment; the stable, high POAA toH₂O₂ ratio peracetic acid composition disclosed in this application(composition I-C as shown in Table 1), and a peracetic acid compositiongenerated by adding a catalase enzyme (100 ppm) to the dilutedcommercial peracid composition (1% POAA) to eliminate H₂O₂ tonon-detectable level prior to the test. The initial POAA levels aretargeted at 30 ppm, and the concentration of POAA was monitored byiodometric titration method during the intended application time of 15minutes. The results are summarized in Table 9 below.

TABLE 9 POAA Stability of Various Peroxyacetic Acid Compositions in UseSolution Containing Used Water from Oil and Gas Well Peracid POAA (ppm)Composition Water 0 min. 5 min. 10 min. 15 min. Commercial POAA WellSite A 30 1.3 0 0 Product Blend Catalase Pretreated Well Site A 30 29 2626 POAA Product Blend POAA Composition Well Site A 30 21 22 22 I-C BlendCommercial POAA Well Site B 30 0 0 0 Product Blend Catalase POAA WellSite B 30 24 22 21 Pretreated Product Blend POAA Composition Well Site B30 21 18 16 I-C Blend

As shown in Table 9, it is surprisingly found that the presence of H₂O₂in the peracetic acid composition has significantly negative impact onthe POAA stability. For example, the commercial peracid product whichcontains around 15% POAA and 10% H₂O₂, lost almost all of its peracidcontent within 5 minutes whereas a hydrogen peroxide depleted version ofthe same (pretreated with catalase enzyme) lost only 3% of its initialactivity in 10 minutes and only about 12% in 15 minutes. For compositionI-C, which contains around 15% peracetic acid but only 1% hydrogenperoxide, lost only about 30% POAA in 15 min. This makes the compositionparticularly useful in fracking water treatment application comparedwith the commercial peracetic acid compositions, as significantly lessamount of POAA was needed for the treatment. The phenomena observedseems to be universal as two different water blend from different wellsites have the similar results as shown in Table 6. While not wishing tobe bound by any particular theory, the results observed may be explainedby the presence of the commonly found sulfur related contaminants in theused well water, which in the presence of H₂O₂, will generate radicalspecie, and these very reactive radical species will then react withPOAA to decompose it.

Example 5. Gelling Test of Peracetic Acid (POAA) Compositions withVarious Levels of Hydrogen Peroxide

Hydrogen peroxide is a known gel breaker in oil and gas gel frackingapplication. It is expected that H₂O₂ presented in a peracid compositionwill have negative impacts on the gel property. This experiment wasdesigned to assess the levels of H₂O₂ in peracid compositions and theirimpacts on the gel property.

The H₂O₂ free peracetic acid was first prepared by treating a commercialperacetic acid product (15% POAA, 10% H₂O₂) with catalase, and after thetreatment, the catalase was confirmed to be inactivated. Then knownamount of H₂O₂ was added to the peracetic acid composition for the test.To ˜500 g of water was added a guar based gel additives except the crosslinker. The mixture was mixed by a blender for ˜10 min., then POAAprepared as described and H₂O₂ was added to the mixture, and the pH ofthe mixture was then adjusted to 11.5 with KOH/K₂CO₃ (11.5 wt %/22.5%),immediately followed by the addition of the cross linker. The kineticviscosity of the mixture was then monitored by a viscometer (Kindler) at275 K during a time period of 2.5 hr. The success criteria is that theviscosity of the mixture maintains 200 cp or higher at the end of thetest. For comparison, a gel mixture with the standard glutaraldehyde asthe alternative biocide was also tested. The test results are shown inFIG. 4.

FIG. 4 clearly shows that under the investigated conditions, at theupper use level of POAA (80 ppm) as a biocide in oil and gas frackingapplications, the presence of 7 ppm of H₂O₂ has no impact on the gelproperty comparing with the standard control (glutaraldehyde), while thepresence of 14 ppm H₂O₂ cause the Gel failure.

Example 6. Gelling Test of a High POAA to H₂O₂ Ratio Peracetic AcidComposition

The gelling experiment as described in Example 5 was carried out usingdifferent levels of a high POAA to H₂O₂ ratio of peracetic acidcomposition (I-C) as disclosed in this application. The results aresummarized in Table 10, along with the results of a commercial peraceticacid product.

TABLE 10 Summary of Kinetic Viscosity Test Results of POAA in A GelFluid Product Commercial POAA Product POAA Composition I-C Use level(15% POAA/10% H₂O₂) (15% POAA/1.2% H₂O₂) 100 ppm 15 ppm POAA/10 ppm H₂O₂15 ppm POAA/1 ppm H₂O₂ Gelling Test Pass Pass 200 ppm 30 ppm POAA/20 ppmH₂O₂ 30 ppm POAA/2 ppm H₂O₂ Gelling Test Fail Pass 500 ppm 75 ppmPOAA/50 ppm H₂O₂ 75 ppm POAA/6 ppm H₂O₂ Gelling Test Fail Pass 1000 ppm150 ppm POAA/100 ppm 150 ppm POAA/12 ppm H₂O₂ H₂O₂ Gelling Test FailFail

The results from Table 10 show the significant advantages ofcompositions in gel fracking applications compared with the commonperacetic acid compositions. For example, at the POAA levels (30 ppm)required for the microorganism kill, the common peracetic acidcomposition will fail the gel properties of the fluid owing to the highlevel of H₂O₂ coexisted. In contrast, the high POAA to H₂O₂ ratioperacetic acid composition I-C has no impact of the gel properties evenused at a much higher level, e.g., 75 ppm POAA.

Example 7. Enthalpy Part I—Potential Enthalpy of High and Low HydrogenPeroxide Peroxyacid Products

Peroxyacids and hydrogen peroxide are characterized by a relatively weak0-0 bond which typically and especially in the case of peroxyacids isprone to homolytic fission which ultimately produces molecular oxygen,water and the parent carboxylic acids. The property of labile homolyticfission is essential to peroxyacids' utility in bleaching,polymerization and antimicrobial applications but it also can createunwelcome hazardous chemical reactions. The eventual liberation ofoxygen is a highly exothermic process (heat producing) and since oxygenis a powerful oxidizing agent, downstream oxidation of organic residuesare possible outcomes producing still greater amounts of heat and gas.The worst case scenario is a violent explosion and or eruption ofcorrosive materials.

For these above reasons peroxyacids fall under the UN category ofdangerous goods and as such it is recommended by the UN that they bethoroughly characterized before determining what restrictions should beimposed for shipping, handling and storage of the same. In general theseguidelines are followed strictly by local authorities and therefore arestriction requiring refrigerated handling and storage for examplewould likely limit sales to only a small minority of potentialcustomers. To avoid such restrictions, most peroxyacid producers firstformulate their products to be intrinsically stable and then addstabilizers such as HEDP to increase assurance against runawayexothermic decay as well as insuring sufficient shelf-life for efficacy.The unfortunate outcome is that the higher hydrogen peroxideconcentrations required for achieving intrinsic stability increase thepotential enthalpy and increase the violence of a runaway chemicalreaction.

As shown in Table 11, formulae III-A, III-B, and III-C possessapproximately twice the potential enthalpy as do formulae I-A, I—B andI—C and yet both deliver 15% peroxyacetic acid. And while the reductionin hydrogen peroxide improves the enthalpic potential for the I-typeformula, only in the I-C case does the product possess sufficient shelfstability to allow manufacturing, warehousing and usage before they havelost excessive portions of their initial peroxyacetic acid.

TABLE 11 Formula Formula Formula Formula Formula Formula Component I-AI-B I-C III-A III-B III-C Acetic acid 83.00 83.96 82.96 43.85 43.8543.85 Hydrogen peroxide (50%) 16.00 16.00 16.00 35.60 35.60 35.60Dequest 2010 (60% HEDP) 1.00 0.00 1.00 1.00 1.00 1.00 Dipicolinic acid(DPA) 0.00 0.10 0.10 0.10 0.10 0.10 Total 100.00 100.00 100.00 100.00100.00 100.00 Theoretical scenario 1 (assume no combustion, onlyperoxide bonds broken and no vaporization of liquids) Heat of Reaction−230 −230 −230 −515 −515 −515 (joule/g) Theoretical scenario 2 (assumethat combustion consumes all of the available oxygen and only volatilesevaporate) Heat of Reaction −745 −745 −745 −1661 −1661 −1661 (joule/g)

Since the O—O bond is intrinsically weak, metal contaminants such as theubiquitous ferric and ferrous ions (iron), catalyze O—O bond fission andthus require that peroxyacids be formulated to include stabilizers suchas metal chelators. And while the typical chelator usually is sufficientto stabilize formulations made with relatively pure chemicals theycannot practically be high enough to overcome gross contaminationevents. In fact, accidental contamination of peroxyacid products is notan unknown event and has caused fatal explosions involving peroxides onmany occasions. Given that the metal chelator stabilizers added forshipping handling and storage can be overwhelmed by a grosscontamination event it is desirable to minimize the potential energyrelative to the peroxyacid content of the product. This is especiallythe case when considering bulk storage scenarios involving for exampleseveral thousand gallons of product.

Currently there are several provisions made for contamination accidents,one is the formulated metal chelating agent always present, the other isgas venting arrangements plumbed into bulk tanks as well as watercoolant kept on standby. Again, in the case of formulae IA and IB whilethey halve the potential enthalpy of a typical 15% POAA product theirvery low hydrogen peroxide levels severely compromise theirshelf-stability. In fact, the stability is so poor for IA and IB that100% decomposition occurs within 1-2 weeks when stored at 40 C for <1week. In example I-C, however, the unique synergistic stabilizercombination is very successful at providing sufficient shelf-life. Thesynergistic stabilizer combination found in I-C allows 15% peroxyaceticacid formula with a greatly reduced hydrogen peroxide and thus a reducedpotential heat of reaction upon a runaway of 230 joules/g(non-combustion scenario) or 745 joules/g if the combustion scenariopredominates. In contrast the more traditional peroxyacid productrepresented by III-A through III-C possesses a potential enthalpy of−515 joules/g (the non-combustion scenario) to −1661 joules/g if thecombustion scenario predominates.

Example 8. Enthalpy Part II—Self-Accelerating Decomposition Testing ofLow Hydrogen Peroxide Peroxyacetic Acid Chemistries

The following SADT procedure is a standardized United Nations protocolto help determine the hazard classes of self-heating substances known asthe “H4 method.” The method is package specific and if the SADTtemperature is found to be 45 degrees C. or lower the product must beshipped, stored and used with rigorous refrigerated controls. Suchcontrolling requirements would likely render a product to be impracticalfor commerce as well as dangerous and unwelcome in most facilities.

In the interest of safety the self-heating behavior of chemistries invery large package sizes is simulated in Dewar flasks which havepreviously been tested to determine that they closely reflect the heattransfer properties of the package. Bulk tanks are the largest potentialpackage sizes and to model their heat transfer properties it isrecommended to use spherical Dewar flasks. The UN committee fortransport of Dangerous Goods further builds a safety margin into the 300gallon and larger package sizes by requiring that they have SADT's≥50deg C. As per UN-H4 guidelines 28.4.1.4.1 if the temperature of thecontent does not exceed the oven temperature by greater than 6 degreesC. within 7 days, the SADT by definition is greater than the oventemperature. The guidelines further define the zero time as when thesample temperature is within 2 degrees of the oven temperature and theyrequire an 80% filled Dewar fitted with temperature monitoring andvented closures. These criteria were fulfilled as 3 spherical Dewarflasks were filled to 80% of full with chemistries I-A, I-B and I-C (seeTable 12 below).

TABLE 12 Component Formula I-A Formula I-B Formula I-C Acetic acid 8383.96 82.96 Hydrogen peroxide (50%) 16 16 16 Dequest 2010 (60% HEDP) 1 01 Dipicolinic acid (DPA) 0 0.1 0.1 Total 100 100 100 Theoreticalscenario 1 (assume no combustion, only peroxide bonds broken and novaporization of liquids) Heat of Reaction (joule/g) −230 −230 −230Observed: Differential Scanning Calorimetry, Heat Flow (between 20 and140 deg C.) Heat of Reaction (joule/g) −205 −147 0 Self AcceleratingDecomposition Study in Bulk Storage Scenario Time before failure in 23 >7 50 deg C. Oven (days):

As can be seen in FIG. 3, formulae I-A and I-B containing respectivelyHEDP only and DPA only stabilizers exceeded the 6 degree exotherm limitwithin 1.5 days and 3 days respectively. The same concentrations of HEDPand DPA when mixed however produced such an extreme stabilization thatthe self-heating effects were not sufficient to reach the oventemperature within the 7 day period. On the basis of the H4 protocol itappears that this synergistic combination uniquely earns the allowanceof bulk storage and transport without refrigeration, at least for thisexemplary type of percarboxylic acid and hydrogen peroxide compositions(e.g., formula I—C type of formula).

Example 9. Quantitation of Peroxide Gases of Decomposition

The volume of peroxides' gases of decomposition was measured using awater filled U-tube fitted with a minimal volume tubing connected to anon-coring syringe needle. The manometer made of pyrex glass was filledpartially with deionized water colored with FD&C blue dye #1 and 1,000ppm of non-ionic surfactant. The dye allows for increased visibility ofthe water columns and the surfactant lowers the surface tension allowingfor unbroken water columns. The manometer was also fitted with a metricruler to allow the convenient determination of the column heightsdifference. Given that 1 atmosphere of pressure corresponds with 1,006cm of water column height and the limit of resolution on the column andruler combination is about 1 mm, the signal/noise ratio approximates10:1.

Procedure. Four head space vials were double rinsed with the samplesolution before adding 5 mL of sample solution (via Repeat Pipettor) andsealing the vials with a silicone backed PTFE septum with aluminum cap.Immediately after sealing the vials the temperature and barometricpressure were recorded. A set of water blank replicates of the samevolume were also included. The sealed vials were stored for 24-48 hoursat ambient temperatures inside a dark cabinet to allow for optimal gaspressure generation.

Calculations. By calibration of the U-tube water column displacementusing a precision gas syringe, the water column height to gas volumeratio was calculated. Using the assumption of peroxide decay tomolecular oxygen (ignoring CO2 or CO gases etc.), these values wereconverted to gas volumes and the loss of available oxygen in the samplewas thereby calculated using the formulae below:2 moles of RCO₃H→2 moles of RCO₂H+1 mole of O₂ (22.4 L of O₂ at standardtemperature and pressure)And2 moles of H₂O₂→2 moles of H₂O+1 mole of O₂ (22.4 L of O₂ at standardtemperature and pressure)

As shown in Table 13 below, the synergistic combination of DPA and HEDPreduced the “Rel. Loss” rate of O₂ for I-C to 1/9 that of I-A and betterthan ⅓^(rd) of that of I-B as measured by the gas volumes of decay. Inaddition it can be seen that the synergistic combination brings itessentially equal to the rate of loss of the more typical commercialperacids as well as that of a 50% active hydrogen peroxide raw material.

TABLE 13 Active DPA Active Net Net Initial Initial Initial Rel. LossConc. HEDP Conc. Init. Ht. Fin. Ht. Gas Gen. O₂ Lost POAA H₂O₂ O₂ O₂Chemistry (ppm) (ppm) (mm) (mm) (mL) (g) (w/w, %) (w/w, %) (w/w, %)(w/w, %) I-A 0 6000 145 415 25.0 0.036 11.48 1.00 2.89 0.27% I-B 1000 0145 266 10.8 0.015 13.03 1.14 3.28 0.10% I-C 1000 6000 143 181 3.0 0.00414.16 1.27 3.58 0.03% D: Commercial 0 9000 143 227 7.4 0.011 14.60 10.608.06 0.03% Peracid 15% PAA/10% Hydrogen peroxide E: Commercial 0 9600143 238 8.4 0.012 5.10 27.00 13.78 0.02% Peracid 5% PAA/27% Hydrogenperoxide F: Hydrogen 0 0 143 275 11.9 0.017 0.00 50.00 23.53 0.02%peroxide, 50% active

Example 10. Hydrogen Sulfide Reduction

Several test were conducted using exemplary formulations of the presentinvention to reduce hydrogen sulfide (H₂S) spiked in distilled water.The ingredients of the exemplary formulations (13523-37-1 and123523-37-2) and a control formulation (Tsunami 100 (EC6734A)) arelisted in the following Table 14.

TABLE 14 13523-37-1 13523-37-1 123523-37-2 123523-37-2 EC6734A EC6734AComposition Wt (g) % Wt (g) % Wt (g) % Acetic acid 719 71.9 769 76.9438.5 43.85 H₂O₂ (50%) 270 27 220 22 0 0 H₂O₂ (35%) 0 0 0 0 508.5 50.85Dequest 10 1 10 1 15 1.5 2010 (60%) DPA 1 0.1 1 0.1 0 0 DI Water 0 0 0 038 3.8 Total 1,000 100 1,000 100 1,000 100 *POAA % 22.3 17.34 14.46 H₂O₂% 3.78 2.20 10.65 POAA/ 5.90 7.88 1.36 H₂O₂

The test results are shown in the following Table 15, and in FIGS. 5A,5B, 6A and 6B. As shown in Table 15, formulation 13523-37-1 at 1,000 ppmreduced H2S about 95%, while formulation 13523-37-1 at 500 ppm reducedH₂S about 80%. Interestingly, a low dosage seems to reduce the H₂S toclose to 50%. When formulation 13523-37-2 was used at 1,000 ppm, H₂Slevel was reduced to 175 ppm. When formulation 13523-37-2 was used at500 pm, H₂S level was reduced to 125 ppm. FIG. 5a shows an example ofhydrogen sulfide (H₂S) reaction in deionized water solution withdifferent relative concentrations of peracetic acid and hydrogenperoxide (see Table 15 for concentrations). Increased concentrations areshown to result in increased destruction of hydrogen sulfide. FIG. 5bshows another example of hydrogen sulfide (H₂S) reaction in deionizedwater solution with different relative concentrations of peracetic acidand hydrogen peroxide (see Table 15 for concentrations). Increasedconcentrations are shown to result in increased destruction of hydrogensulfide.

TABLE 15 H₂S Lease Name & Number Sample Description Concentration (ppm)d H₂O spiked with H₂S Blank 525 d H₂O spiked with H₂S 13523-37-1 400 ppm150 d H₂O spiked with H₂S 123523-37-2 400 ppm 190 d H₂O spiked with H₂S13523-37-1 200 ppm 285 d H₂O spiked with H₂S 123523-37-2 200 ppm 285 dH₂O spiked with H₂S 13523-37-1 1,000 ppm 25 d H₂O spiked with H₂S Blank600 d H₂O spiked with H₂S 13523-37-1 500 ppm 125 d H₂O spiked with H₂S123523-37-2 500 ppm 125 d H₂O spiked with H₂S EC6734A 500 ppm 150 d H₂Ospiked with H₂S 13523-37-1 1,000 ppm 25 d H₂O spiked with H₂S123523-37-2 1,000 ppm 175 d H₂O spiked with H₂S EC6734A 1,000 ppm 75

H. EXEMPLARY EMBODIMENTS

The present invention is further illustrated by the following exemplaryembodiments:

1. A composition, which composition comprises:

1) a C₁-C₂₂ carboxylic acid;

2) a C₁-C₂₂ percarboxylic acid;

3) hydrogen peroxide;

4) a first stabilizing agent, which is a picolinic acid or a compoundhaving the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

-   -   or a salt thereof;    -   or a compound having the following Formula (IB):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

5) a second stabilizing agent, which is a compound having the followingFormula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof; and

wherein said hydrogen peroxide has a concentration of at least about 0.1wt-%, the C₁-C₂₂ percarboxylic acid has a concentration of at leastabout 2 times of the concentration of said hydrogen peroxide, and saidcomposition has a pH at about 4 or less.

2. The composition of embodiment 1, wherein the C₁-C₂₂ percarboxylicacid has a concentration of at least about 6 times of the concentrationof the hydrogen peroxide.

3. The composition of embodiment 1, wherein the C₁-C₂₂ percarboxylicacid has a concentration of at least about 10 times of the concentrationof the hydrogen peroxide.

4. The composition of any of embodiments 1-3, wherein the C₁-C₂₂carboxylic acid is a C₂-C₂₀ carboxylic acid.

5. The composition of any of embodiments 1-4, wherein the C₁-C₂₂carboxylic acid comprises acetic acid, octanoic acid and/or sulfonatedoleic acid.

6. The composition of any of embodiments 1-5, wherein the C₁-C₂₂carboxylic acid has a concentration from about 10 wt-% to about 90 wt-%.

7. The composition of any of embodiments 1-5, wherein the C₁-C₂₂carboxylic acid has a concentration from about 20 wt-% to about 80 wt-%.

8. The composition of any of embodiments 1-7, wherein the C₁-C₂₂percarboxylic acid is a C₂-C₂₀ percarboxylic acid.

9. The composition of any of embodiments 1-8, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

10. The composition of any of embodiments 1-9, wherein the C₁-C₂₂percarboxylic acid has a concentration from about 1 wt-% to about 40wt-%.

11. The composition of any of embodiments 1-9, wherein the C₁-C₂₂percarboxylic acid has a concentration from about 1 wt-% to about 20wt-%.

12. The composition of any of embodiments 1-11, wherein the hydrogenperoxide has a concentration from about 0.5 wt-% to about 10 wt-%.

13. The composition of any of embodiments 1-11, wherein the hydrogenperoxide has a concentration from about 1 wt-% to about 2 wt-%.

14. The composition of any of embodiments 1-13, wherein the C₁-C₂₂carboxylic acid is acetic acid and the C₁-C₂₂ percarboxylic acid isperacetic acid.

15. The composition of any of embodiments 1-14, wherein the C₁-C₂₂carboxylic acid has a concentration of about 70 wt-%, the C₁-C₂₂percarboxylic acid has a concentration of about 15 wt-%, and thehydrogen peroxide has a concentration of at least about 1 wt-%.

16. The composition of any of embodiments 1-15, wherein the firststabilizing agent is a picolinic acid, or a salt thereof.

17. The composition of any of embodiments 1-15, wherein the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.

18. The composition of any of embodiments 1-17, wherein the firststabilizing agent has a concentration from about 0.005 wt-% to about 5wt-%.

19. The composition of any of embodiments 1-17, wherein the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%.

20. The composition of any of embodiments 1-19, wherein the secondstabilizing agent is 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP),or a salt thereof.

21. The composition of any of embodiments 1-20, wherein the secondstabilizing agent has a concentration from about 0.1 wt-% to about 10wt-%.

22. The composition of any of embodiments 1-20, wherein the secondstabilizing agent has a concentration from about 0.5 wt-% to about 5wt-%.

23. The composition of any of embodiments 1-20, wherein the secondstabilizing agent has a concentration from about 0.6 wt-% to about 1.8wt-%.

24. The composition of any of embodiments 1-23, which further comprisesa substance that aids solubilization of the first and/or secondstabilizing agent(s).

25. The composition of any of embodiments 1-24, wherein the firststabilizing agent is a 2,6-pyridinedicarboxylic acid, or a salt thereof,and the second stabilizing agent is HEDP, or a salt thereof.

26. The composition of any of embodiments 1-25, wherein the first andsecond stabilizing agents delay or prevent the composition fromexceeding its self-accelerating decomposition temperature (SADT).

27. The composition of any of embodiments 1-26, which retains at leastabout 80% of the C₁-C₂₂ percarboxylic acid activity after storage ofabout 30 days at about 50° C.

28. A method for storing a percarboxylic acid containing composition,which method comprises storing a composition of any of embodiments 1-27,wherein said composition retains at least about 80% of the C₁-C₂₂percarboxylic acid activity after storage of about 30 days at about 50°C.

29. A method for transporting a percarboxylic acid containingcomposition, which method comprises transporting a composition of any ofembodiments 1-27, wherein the SADT of said composition is elevated to atleast 45° C. during transportation.

30. A method for treating water, which method comprises providing acomposition of any of embodiments 1-27 to a water source in need oftreatment to form a treated water source, wherein said treated watersource comprises from about 1 ppm to about 1,000 ppm of said C₁-C₂₂percarboxylic acid.

31. The method of embodiment 30, wherein the water source in need oftreatment is selected from the group consisting of fresh water, pondwater, sea water, produced water and a combination thereof.

32. The method of embodiment 31, wherein the water source comprises atleast about 1 wt-% produced water.

33. The method of any of embodiments 30-32, wherein the treated watersource comprises from about 10 ppm to about 200 ppm of the C₁-C₂₂percarboxylic acid.

34. The method of any of embodiments 30-33, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

35. The method of any of embodiments 30-34, wherein the treated watersource comprises from about 1 ppm to about 15 ppm of the hydrogenperoxide.

36. The method of any of embodiments 30-35, wherein the treated watersource retains at least about 60% of the initial C₁-C₂₂ percarboxylicacid activity in the treated water source for 15 minutes after thetreated water source is formed.

37. The method of any of embodiments 30-36, wherein the level of amicroorganism, if present in the water source, is stabilized or reduced.

38. The method of any of embodiments 30-37, wherein antimicrobialefficacy of the composition of any of embodiments 1-27 on the treatedwater source is comparable to antimicrobial effect of a water sourcethat does not contain produced water.

39. The method of any of embodiments 30-38, wherein the treated watersource reduces corrosion caused by hydrogen peroxide and reducesmicrobial-induced corrosion, and the composition of any of embodiments1-27 does not substantially interfere with a friction reducer, aviscosity enhancer, other functional ingredients present in the treatedwater source, or a combination thereof.

40. The method of any of embodiments 30-39, which further comprisesadding a peroxidase or a catalase to the water source before acomposition of any of embodiments 1-27 is provided to the water source,and wherein the peroxidase or a catalase further reduces the hydrogenperoxide level in the treated water source.

41. The method of any of embodiments 30-40, which further comprisesdirecting the treated water source into a subterranean environment ordisposing of the treated water source.

42. The method of any of embodiments 30-41, wherein the water sourcedoes not comprise reuse water, the treated water source comprises fromabout 10 ppm to about 20 ppm of the C₁-C₂₂ percarboxylic acid and fromabout 1 ppm to about 2 ppm of hydrogen peroxide and the treated watersource does not comprise a friction reducer and/or a rheology modifier.

43. The method of any of embodiments 30-42, wherein the water source isa blended water source that comprises about 80 wt-% fresh water or pondwater and about 20 wt-% of reuse water, the treated water sourcecomprises from about 25 ppm to about 35 ppm of the C₁-C₂₂ percarboxylicacid and from about 2 ppm to about 3 ppm of hydrogen peroxide andcatalase, the treated water source does not comprise a friction reducerand/or a rheology modifier, and the treated water source is formedbefore reaching a blending tub.

44. The method of any of embodiments 30-43, wherein the water source isa blended water source that comprises about 80 wt-% fresh water or pondwater and about 20 wt-% of reuse water, the treated water sourcecomprises from about 25 ppm to about 35 ppm of the C₁-C₂₂ percarboxylicacid and from about 2 ppm to about 3 ppm of hydrogen peroxide andcatalase, the treated water source comprises a friction reducer and/or arheology modifier, and the treated water source is formed in a blendingtub.

45. The method of any of embodiments 30-44, wherein the treated watersource comprises from about 30 ppm or less of the C₁-C₂₂ percarboxylicacid and about 0.5 ppm or less of the hydrogen peroxide, the treatedwater source comprises a friction reducer and/or a rheology modifier,and the treated water source is directed into or is at a subterraneanenvironment.

46. A composition, which composition comprises:

1) a C₁-C₂₂ carboxylic acid;

2) a C₁-C₂₂ percarboxylic acid;

3) hydrogen peroxide;

4) a first stabilizing agent, which is a picolinic acid or a compoundhaving the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

-   -   or a salt thereof;    -   or a compound having the following Formula (IB):

wherein

R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

5) a second stabilizing agent, which is a compound having the followingFormula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof;

6) a friction reducer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 20 ppm, and the C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

47. The composition of embodiment 46, wherein the hydrogen peroxide hasa concentration of about 1 ppm to about 10 ppm.

48. The composition of embodiment 46 or 47, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 6 times of theconcentration of the hydrogen peroxide.

49. The composition of any of embodiments 46-48, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 10 times of theconcentration of the hydrogen peroxide.

50. The composition of any of embodiments 46-49, wherein the frictionreducer is a polyacrylamide polymer and/or copolymer, or anacrylamide-derived polymer and/or copolymer.

51. The composition of any of embodiments 46-50, wherein the frictionreducer has a concentration from about 50 ppm to about 5,000 ppm,preferably from about 100 ppm to about 1,000 ppm.

52. The composition of any of embodiments 46-51, which further comprisesa proppant, a surfactant and/or a scale inhibitor.

53. The composition of embodiment 52, wherein the proppant is a sand ora ceramic bead.

54. The composition of embodiment 52, wherein the scale inhibitor is apolymer, a phosphonate or a phosphate ester.

55. The composition of any of embodiments 46-54, wherein the C₁-C₂₂percarboxylic acid is a C₂-C₂₀ percarboxylic acid.

56. The composition of any of embodiments 46-55, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

57. The composition of any of embodiments 46-56, wherein the C₁-C₂₂percarboxylic acid has a concentration from about 10 ppm to about 30 ppmand the hydrogen peroxide has a concentration from about 1 ppm to about3 ppm.

58. The composition of any of embodiments 46-57, wherein the firststabilizing agent is a picolinic acid, or a salt thereof.

59. The composition of any of embodiments 46-57, wherein the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.

60. The composition of any of embodiments 46-59, wherein the firststabilizing agent has a concentration from about 0.005 wt-% to about 5wt-%.

61. The composition of any of embodiments 46-59, wherein the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%.

62. The composition of any of embodiments 46-61, wherein the secondstabilizing agent is 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP),or a salt thereof.

63. The composition of any of embodiments 46-62, wherein the secondstabilizing agent has a concentration from about 0.1 wt-% to about 10wt-%.

64. The composition of any of embodiments 46-62, wherein the secondstabilizing agent has a concentration from about 0.5 wt-% to about 5wt-%.

65. The composition of any of embodiments 46-62, wherein the secondstabilizing agent has a concentration from about 0.6 wt-% to about 1.8wt-%.

66. The composition of any of embodiments 46-65, wherein the firststabilizing agent is a 2,6-pyridinedicarboxylic acid, or a salt thereof,and the second stabilizing agent is HEDP, or a salt thereof.

67. The composition of any of embodiments 46-66, which retains at leastabout 60% of the initial C₁-C₂₂ percarboxylic acid activity for 15minutes after the composition is formed.

68. The composition of any of embodiments 46-67, wherein the hydrogenperoxide concentration is further reduced by a peroxidase or a catalase.

69. The composition of any of embodiments 46-68, which further comprisesa substance that aids solubilization of the first and/or secondstabilizing agent(s).

70. A method for slick water fracturing, which method comprisesdirecting a composition of any of embodiments 46-69 into a subterraneanenvironment.

71. The method of embodiment 70, wherein the composition is directedinto a subterranean environment at a speed faster than 30 barrel(bbl)/min.

72. The method of embodiment 71, wherein the composition is directedinto a subterranean environment at a speed from about 50 bbl/min. toabout 100 bbl/min. 73. The method of any of embodiments 70-72, whereinthe subterranean environment comprises a well in a shale gas and/or oilreservoir.

74. The method of any of embodiments 70-73, wherein the composition ispumped down a well-bore.

75. A composition, which composition comprises:

1) a C₁-C₂₂ carboxylic acid;

2) a C₁-C₂₂ percarboxylic acid;

3) hydrogen peroxide;

4) a first stabilizing agent, which is a picolinic acid or a compoundhaving the following Formula (IA):

wherein

R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

or a compound having the following Formula (TB):

wherein

R¹ is OH or —R^(1a)R^(1b), wherein R^(1a) and R^(1b) are independentlyhydrogen or (C₁-C₆)alkyl;

R² is OH or —NR^(2a)R^(2b), wherein R^(2a) and R^(2b) are independentlyhydrogen or (C₁-C₆)alkyl;

each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and

n is a number from zero to 3;

or a salt thereof;

5) a second stabilizing agent, which is a compound having the followingFormula (IIA):

wherein

R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

R⁵ is (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and

R⁶ is hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;

or a salt thereof;

or a compound having the following Formula (IIB):

wherein

R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl, (C₂-C₆)alkenylor (C₂-C₆)alkynyl, or C₆₋₂₀ aryl;

or a salt thereof;

6) a viscosity enhancer; and

wherein said hydrogen peroxide has a concentration of about 1 ppm toabout 15 ppm, and said C₁-C₂₂ percarboxylic acid has a concentration ofat least about 2 times of the concentration of said hydrogen peroxide.

76. The composition of embodiment 75, wherein the hydrogen peroxide hasa concentration of about 1 ppm to about 10 ppm.

77. The composition of embodiment 75 or 76, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 6 times of theconcentration of the hydrogen peroxide.

78. The composition of any of embodiments 75-77, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 10 times of theconcentration of the hydrogen peroxide.

79. The composition of any of embodiments 75-78, wherein the viscosityenhancer is a conventional linear gel, a borate-crosslinked gel, anorganometallic-crosslinked gel or an aluminum phosphate-ester oil gel.

80. The composition of any of embodiments 75-79, wherein the viscosityenhancer has a concentration from about 2 to about 100 units of poundsper thousand gallons, preferably from about 5 to about 65 units ofpounds per thousand gallons.

81. The composition of any of embodiments 75-80, which further comprisesa proppant, a surfactant, a scale inhibitor and/or a breaker.

82. The composition of embodiment 81, wherein the proppant is a sand ora ceramic bead.

83. The composition of embodiment 81, wherein the scale inhibitor is apolymer, a phosphonate or a phosphate ester.

84. The composition of embodiment 81, wherein the breaker is anoxidizer, an enzyme or a pH modifier.

85. The composition of any of embodiments 75-84, wherein the C₁-C₂₂percarboxylic acid is a C₂-C₂₀ percarboxylic acid.

86. The composition of any of embodiments 75-85, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

87. The composition of any of embodiments 75-86, wherein the C₁-C₂₂percarboxylic acid has a concentration that is effective for itsanti-microbial function and the hydrogen peroxide has a concentrationthat will not cause gel failure.

88. The composition of embodiment 87, wherein the hydrogen peroxide hasa concentration that is about 14 ppm or less.

89. The composition of any of embodiments 75-88, wherein the C₁-C₂₂percarboxylic acid has a concentration from about 10 ppm to about 30 ppmand the hydrogen peroxide has a concentration from about 1 ppm to about3 ppm.

90. The composition of any of embodiments 75-89, wherein the firststabilizing agent is a picolinic acid, or a salt thereof.

91. The composition of any of embodiments 75-90, wherein the firststabilizing agent is 2,6-pyridinedicarboxylic acid, or a salt thereof.

92. The composition of any of embodiments 75-91, wherein the firststabilizing agent has a concentration from about 0.005 wt-% to about 5wt-%.

93. The composition of any of embodiments 75-92, wherein the firststabilizing agent has a concentration from about 0.05 wt-% to about 0.15wt-%.

94. The composition of any of embodiments 75-93, wherein the secondstabilizing agent is 1-hydroxy ethylidene-1,1-diphosphonic acid (HEDP),or a salt thereof.

95. The composition of any of embodiments 75-94, wherein the secondstabilizing agent has a concentration from about 0.1 wt-% to about 10wt-%.

96. The composition of any of embodiments 75-94, wherein the secondstabilizing agent has a concentration from about 0.5 wt-% to about 5wt-%.

97. The composition of any of embodiments 75-94, wherein the secondstabilizing agent has a concentration from about 0.6 wt-% to about 1.8wt-%.

98. The composition of any of embodiments 75-97, wherein the firststabilizing agent is a 2,6-pyridinedicarboxylic acid, or a salt thereof,and the second stabilizing agent is HEDP, or a salt thereof.

99. The composition of any of embodiments 75-98, which retains at leastabout 60% of the initial C₁-C₂₂ percarboxylic acid activity for 15minutes after the composition is formed.

100. The composition of any of embodiments 75-99, wherein the hydrogenperoxide concentration is further reduced by a peroxidase or a catalase.

101. The composition of any of embodiments 75-100, which furthercomprises a substance that aids solubilization of the first and/orsecond stabilizing agent(s).

102. A method for high-viscosity fracturing, which method comprisesdirecting a composition of any of embodiments 75-101 into a subterraneanenvironment.

103. The method of embodiment 102, wherein the subterranean environmentcomprises a well in a gas and/or oil.

104. A method for treating a target, which method comprises a step ofcontacting a target with a diluted composition of any of embodiments1-27 to form a treated target composition, wherein said treated targetcomposition comprises from about 1 ppm to about 10,000 ppm of saidC₁-C₂₂ percarboxylic acid, and said contacting step lasts for sufficienttime to stabilize or reduce microbial population in and/or on saidtarget or said treated target composition.

105. The method of embodiment 104, wherein the target is a food item ora plant item and/or at least a portion of a medium, a container, anequipment, a system or a facility for growing, holding, processing,packaging, storing, transporting, preparing, cooking or serving the fooditem or the plant item

106. The method of embodiment 105, wherein the plant item is a grain,fruit, vegetable or flower plant item.

107. The method of embodiment 105, wherein the plant item is a livingplant item or a harvested plant item

108. The method of embodiment 105, wherein the plant item comprises aseed, a tuber, a growing plant, a cutting, or a root stock

109. The method of embodiment 105, which is used for treating a livingplant tissue comprising treating the plant tissue with a dilutedcomposition of any of embodiments 1-27 to stabilize or reduce microbialpopulation in and/or on the plant tissue.

110. The method of embodiment 105, which is used for growing a plant ona hydroponic substrate in a hydroponic liquid supply medium, comprising:

(a) establishing a growing and living plant tissue in the hydroponicsubstrate;

(b) contacting the living plant tissue, the hydroponic substrate and thehydroponic liquid with a diluted composition of any of embodiments 1-27to stabilize or reduce microbial population in and/or on the livingplant tissue; and

(c) harvesting a usable plant product with reduced microbialcontamination.

111. The method of embodiment 105, wherein the food item is selectedfrom the group consisting of an animal product, e.g., an animal carcassor an egg, a fruit item, a vegetable item, and a grain item.

112. The method of embodiment 111, wherein the animal carcass isselected from the group consisting of a beef, pork, veal, buffalo, lamb,fish, sea food and poultry carcass.

113. The method of embodiment 112, wherein the sea food carcass isselected from the group consisting of scallop, shrimp, crab, octopus,mussel, squid and lobster.

114. The method of embodiment 111, wherein the fruit item is selectedfrom the group consisting of a botanic fruit, a culinary fruit, a simplefruit, an aggregate fruit, a multiple fruit, a berry, an accessory fruitand a seedless fruit.

115. The method of embodiment 111, wherein the vegetable item isselected from the group consisting of a flower bud, a seed, a leaf, aleaf sheath, a bud, a stem, a stem of leaves, a stem shoot, a tuber, awhole-plant sprout, a root and a bulb.

116. The method of embodiment 111, wherein the grain item is selectedfrom the group consisting of maize, rice, wheat, barley, sorghum,millet, oat, triticale, rye, buckwheat, fonio and quinoa.

117. The method of embodiment 105, wherein the target is at least aportion of a container, an equipment, a system or a facility forholding, processing, packaging, storing, transporting, preparing,cooking or serving the food item or the plant item.

118. The method of embodiment 105, wherein the target is at least aportion of a container, an equipment, a system or a facility forholding, processing, packaging, storing, transporting, preparing,cooking or serving a meat item, a fruit item, a vegetable item, or agrain item.

119. The method of embodiment 105, wherein the target is at least aportion of a container, an equipment, a system or a facility forholding, processing, packaging, storing, or transporting an animalcarcass.

120. The method of embodiment 104, wherein the target is at least aportion of a container, an equipment, a system or a facility used infood processing, food service or health care industry.

121. The method of embodiment 104, wherein the target is at least aportion of a fixed in-place process facility.

122. The method of embodiment 121, wherein the fixed in-place processfacility comprises a milk line dairy, a continuous brewing system, apumpable food system or a beverage processing line.

123. The method of embodiment 104, wherein the target is at least aportion of a solid surface or liquid media.

124. The method of embodiment 123, wherein the solid surface is aninanimate solid surface contaminated by a biological fluid comprisingblood, other hazardous body fluid, or a mixture thereof.

125. The method of embodiment 123, wherein the solid surface is acontaminated surface.

126. The method of embodiment 125, wherein the contaminated surfacecomprises the surface of food service wares or equipment, or the surfaceof a fabric.

127. The method of any of embodiments 104-126, wherein the treatedtarget composition comprises from about 10 ppm to about 200 ppm of theC₁-C₂₂ percarboxylic acid.

128. The method of any of embodiments 104-127, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

129. The method of any of embodiments 104-128, wherein the treatedtarget composition comprises from about 1 ppm to about 15 ppm of thehydrogen peroxide.

130. The method of any of embodiments 104-129, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 3 times of theconcentration of the hydrogen peroxide.

131. The method of any of embodiments 104-130, wherein the firststabilizing agent is a 2,6-pyridinedicarboxylic acid, or a salt thereof,and the second stabilizing agent is HEDP, or a salt thereof.

132. The method of any of embodiments 104-131, wherein the treatedtarget composition retains at least about 60% of the initial C₁-C₂₂percarboxylic acid activity in the treated target composition for 15minutes after the treated target composition is formed.

133. The method of any of embodiments 104-132, wherein the contactingstep lasts for at least 10 seconds.

134. The method of any of embodiments 104-133, wherein the dilutedcomposition of any of embodiments 1-27 is applied to the target by meansof a spray, a fog, or a foam.

135. The method of any of embodiments 104-134, wherein the dilutedcomposition of any of embodiments 1-27 is applied to the target byapplying in the form of a thickened or gelled solution.

136. The method of any of embodiments 104-134, wherein all or part ofthe target is dipped in the diluted composition of any of embodiments1-27.

137. The method of embodiment 136, wherein the diluted composition ofany of embodiments 1-27 is agitated.

138. The method of any of embodiments 104-134, wherein the dilutedcomposition of any of embodiments 1-27 is sprayed onto the carcass at apressure of at least 50 psi at a temperature of up to about 60° C.,resulting in a contact time of at least 30 seconds.

139. The method of any of embodiments 104-138, which further comprises avacuum treatment step.

140. The method of any of embodiments 104-139, which further comprises astep of applying an activated light source to the target.

141. The method of any of embodiments 104-140, wherein the microbialpopulation in and/or on the target or the treated target composition isreduced by at least one log₁₀.

142. The method of any of embodiments 104-140, wherein the microbialpopulation in and/or on the target or the treated target composition isreduced by at least two log₁₀.

143. The method of any of embodiments 104-140, wherein the microbialpopulation in and/or on the target or the treated target composition isreduced by at least three log₁₀.

144. The method of any of embodiments 104-143, wherein the microbialpopulation comprises a prokaryotic microbial population.

145. The method of embodiment 144, wherein the prokaryotic microbialpopulation comprises a bacterial or an archaeal population.

146. The method of any of embodiments 104-143, wherein the microbialpopulation comprises an eukaryotic microbial population.

147. The method of embodiment 146, wherein the eukaryotic microbialpopulation comprises a protozoal or fungal population.

148. The method of any of embodiments 104-143, wherein the microbialpopulation comprises a viral population.

149. The method of any of embodiments 104-148, wherein the target is afood item or a plant item and the contacting step minimizes or does notinduce an organoleptic effect in and/or on the food item or a plantitem.

150. The method of any of embodiments 104-149, which is conducted at atemperature ranging from about 0° C. to about 70° C.

151. A method for reducing the level of hydrogen sulfide (H₂S),hydrosulfuric acid or a salt thereof in a water source, which methodcomprises a step of contacting a water source with a diluted compositionof any of embodiments 1-27 to form a treated water source, wherein saidtreated water source comprises from about 1 ppm to about 10,000 ppm ofsaid C₁-C₂₂ percarboxylic acid, and said contacting step lasts forsufficient time to stabilize or reduce the level of H₂S, hydrosulfuricacid or a salt thereof in said treated water source.

152. The method of embodiment 151, wherein the water source is selectedfrom the group consisting of fresh water, pond water, sea water,produced water and a combination thereof.

153. The method of embodiment 152, wherein the water source comprises atleast about 1 wt-% produced water.

154. The method of any of embodiments 151-153, wherein the treatedtarget composition comprises from about 10 ppm to about 1,000 ppm of theC₁-C₂₂ percarboxylic acid.

155. The method of any of embodiments 151-154, wherein the C₁-C₂₂percarboxylic acid comprises peroxyacetic acid, peroxyoctanoic acidand/or peroxysulfonated oleic acid.

156. The method of any of embodiments 151-155, wherein the treatedtarget composition comprises from about 1 ppm to about 15 ppm of thehydrogen peroxide.

157. The method of any of embodiments 151-156, wherein the C₁-C₂₂percarboxylic acid has a concentration of at least about 3 times of theconcentration of the hydrogen peroxide.

158. The method of any of embodiments 151-157, wherein the firststabilizing agent is a 2,6-pyridinedicarboxylic acid, or a salt thereof,and the second stabilizing agent is HEDP, or a salt thereof.

159. The method of any of embodiments 151-158, wherein the level of H₂S,hydrosulfuric acid or a salt thereof in the treated water source isreduced by at least 10% from the untreated level.

160. The method of any of embodiments 151-159, wherein at least aportion of the water source is obtained or derived from a subterraneanenvironment.

161. The method of any of embodiments 151-160, which further comprisesdirecting the treated water source into a subterranean environment ordisposing of the treated water source.

The invention claimed is:
 1. A composition, which compositioncomprises: 1) a C₁-C₂₂ carboxylic acid; 2) a C₁-C₂₂ percarboxylic acid;3) hydrogen peroxide; 4) a first stabilizing agent that is a2,6-pyridinedicarboxylic acid, or a salt thereof 5) a second stabilizingagent that is HEDP, or a salt thereof; and wherein said hydrogenperoxide has a concentration of at least about 0.1 wt-%, said C₁-C₂₂percarboxylic acid has a concentration of at least about 2 times of theconcentration of said hydrogen peroxide, said composition has a pH atabout 4 or less, said C₁-C₂₂ carboxylic acid is acetic acid and saidC₁-C₂₂ percarboxylic acid is peracetic acid, and on or after reachingequilibrium, said composition retains a greater amount of said C₁-C₂₂percarboxylic acid after storage at about 50° C. for at least 7 dayscompared to an otherwise identical composition containing only saidfirst stabilizing agent or said second stabilizing agent stored underthe same conditions.
 2. The composition of claim 1, wherein theperacetic acid has a concentration of at least about 3 times of theconcentration of the hydrogen peroxide.
 3. The composition of claim 1,which further comprises, octanoic acid and/or sulfonated oleic acid. 4.The composition of claim 1, wherein the peracetic acid has aconcentration of about 10 wt-% to about 30 wt-%.
 5. The composition ofclaim 1, wherein the first and second stabilizing agents delay orprevent the composition from exceeding its self-acceleratingdecomposition temperature (SADT).
 6. The composition of claim 1, whichretains at least about 80% of the peracetic acid after storage at about50° C. for at least 7 days.
 7. The composition of claim 1, which retainsa greater amount of the peracetic acid compared to the otherwiseidentical composition containing only the first stabilizing agent or thesecond stabilizing agent after storage for at least 14 days at about 50°C.
 8. The composition of claim 7, wherein the composition retains atleast 80% of the peracetic acid after said storage.
 9. The compositionof claim 1, wherein the first stabilizing agent has a concentration fromabout 0.005 wt-% to about 5 wt-%.
 10. The composition of claim 1,wherein the second stabilizing agent has a concentration from about 0.1wt-% to about 10 wt-%.
 11. The composition of claim 1, which furthercomprises a substance that aids solubilization of the first and/orsecond stabilizing agent(s).
 12. A composition, comprising: 1) a C₁-C₂₂carboxylic acid wherein the C₁-C₂₂ carboxylic acid is acetic acid; 2) atleast about 0.1 wt-% hydrogen peroxide; 3) about 10 wt-% to about 30wt-% C₁-C₂₂ percarboxylic acid, wherein the C₁-C₂₂ percarboxylic acidhas a concentration of at least about 2 times of the concentration ofthe hydrogen peroxide and the C₁-C₂₂ percarboxylic acid is peraceticacid; 4) a first stabilizing agent that is a 2,6-pyridinedicarboxylicacid, or a salt thereof; 5) a second stabilizing agent that is HEDP, ora salt thereof; and wherein, on or after reaching equilibrium, saidcomposition retains at least 80% of the C₁-C₂₂ percarboxylic acid afterstorage at about 50° C. for at least 7 days.
 13. The composition ofclaim 12, wherein the composition retains at least 80% of the C₁-C₂₂percarboxylic acid after said storage for 14 days.
 14. The compositionof claim 12, wherein the composition retains at least 80% of the C₁-C₂₂percarboxylic acid after said storage for 21 days.
 15. A composition,comprising: 1) a C₁-C₂₂ carboxylic acid; 2) at least about 0.1 wt-%hydrogen peroxide; 3) about 10 wt-% to about 30 wt-% C₁-C₂₂percarboxylic acid, wherein the C₁-C₂₂ percarboxylic acid has aconcentration of at least about 2 times of the concentration of thehydrogen peroxide; 4) a first stabilizing agent, which is a picolinicacid or a compound having the following Formula (IA):

wherein R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) areindependently hydrogen or (C₁-C₆)alkyl; R² is OH or —NR^(2a)R^(2b)),wherein R^(2a) and R^(2b) are independently hydrogen or (C₁-C₆)alkyl;each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and n is a number from zero to 3; or a salt thereof; or a compoundhaving the following Formula (IB):

wherein R¹ is OH or —NR^(1a)R^(1b), wherein R^(1a) and R^(1b) areindependently hydrogen or (C₁-C₆)alkyl; R² is OH or —NR^(2a)R^(2b)),wherein R^(2a) and R^(2b) are independently hydrogen or (C₁-C₆)alkyl;each R³ is independently (C₁-C₆)alkyl, (C₂-C₆)alkenyl or (C₂-C₆)alkynyl;and n is a number from zero to 3; or a salt thereof; 5) a secondstabilizing agent, which is a compound having the following Formula(IIA):

wherein R¹, R², R³, and R⁴ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆-C₂₀ aryl; R⁵ is (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl; and R⁶ is hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl; or a compound having the followingFormula (IIB):

wherein R¹, R², and R³ are independently hydrogen, (C₁-C₆)alkyl,(C₂-C₆)alkenyl or (C₂-C₆)alkynyl, or C₆-C₂₀ aryl; or a salt thereof; andwherein, on or after reaching equilibrium, the composition retains agreater amount of the C₁-C₂₂ percarboxylic acid compared to an otherwiseidentical composition containing only the first stabilizing agent or thesecond stabilizing agent after storage for 7 days at about 50° C.
 16. Acomposition, which composition comprises: 1) a C₁-C₂₂ carboxylic acid;2) a C₁-C₂₂ percarboxylic acid; 3) hydrogen peroxide; 4) a firststabilizing agent that is a 2,6-pyridinedicarboxylic acid, or a saltthereof 5) a second stabilizing agent that is HEDP, or a salt thereof;and wherein said hydrogen peroxide has a concentration of at least about0.1 wt-%, said C₁-C₂₂ percarboxylic acid has a concentration of at leastabout 2 times of the concentration of said hydrogen peroxide, saidcomposition has a pH at about 4 or less, said C₁-C₂₂ carboxylic acid isacetic acid and said C₁-C₂₂ percarboxylic acid is peracetic acid, and onor after reaching equilibrium, said composition retains a greater amountof said C₁-C₂₂ percarboxylic acid after storage at about 50° C. for atleast 14 days compared to an otherwise identical composition containingonly said first stabilizing agent or said second stabilizing agentstored under the same conditions.
 17. The composition of claim 16, whichretains a greater amount of said C₁-C₂₂ percarboxylic acid after storageat about 50° C. for at least 21 days compared to an otherwise identicalcomposition containing only said first stabilizing agent or said secondstabilizing agent stored under the same conditions.
 18. The compositionof claim 16, which retains a greater amount of said C₁-C₂₂ percarboxylicacid after storage at about 50° C. for at least 28 days compared to anotherwise identical composition containing only said first stabilizingagent or said second stabilizing agent stored under the same conditions.19. The composition of claim 16, which retains a greater amount of saidC₁-C₂₂ percarboxylic acid after storage at about 50° C. for at least 35days compared to an otherwise identical composition containing only saidfirst stabilizing agent or said second stabilizing agent stored underthe same conditions.
 20. The composition of claim 16, which retains agreater amount of said C₁-C₂₂ percarboxylic acid after storage at about50° C. for at least 42 days compared to an otherwise identicalcomposition containing only said first stabilizing agent or said secondstabilizing agent stored under the same conditions.
 21. The compositionof claim 16, wherein the peracetic acid has a concentration of at leastabout 3 times of the concentration of the hydrogen peroxide.
 22. Thecomposition of claim 16, which further comprises octanoic acid and/orsulfonated oleic acid.
 23. The composition of claim 16, wherein theperacetic acid has a concentration of about 10 wt-% to about 30 wt-%.24. The composition of claim 16, wherein the first and secondstabilizing agents delay or prevent the composition from exceeding itsself-accelerating decomposition temperature (SADT).
 25. The compositionof claim 16, wherein the composition retains at least 80% of theperacetic acid after said storage.
 26. The composition of claim 16,wherein the first stabilizing agent has a concentration from about 0.005wt-% to about 5 wt-%.
 27. The composition of claim 16, wherein thesecond stabilizing agent has a concentration from about 0.1 wt-% toabout 10 wt-%.
 28. The composition of claim 16, which further comprisesa substance that aids solubilization of the first and/or secondstabilizing agent(s).